Предпосылки
Как-то наткнулся на такую информацию:
Интересное совпадение. Решил поискать дальше, кто-то писал что сумма по одному разряду 5. Это понятно, 6+8=14, 1+4=5. На тот момент я задался вопросом, а сколько таких дат, насколько часто они встречаются? Самый простой ответ - каждый месяц по дате. Месяц за месяцем во мне зрело любопытство.
Решение
Много позже решил написать программку, которая бы распечатывала такие числа. Но чтобы что-то разместить на гитхабе, нужно было привести в порядок. Сделал интерфейс командной строки и программка на гитхабе:
https://github.com/yatsvic/dates-sum
Для решения выбрал язык Scala и для сборки Gradle.
Результаты
Посмотрим, какие даты имеют сумму 68 с 1900 до 2100 года.
$ gradle run --args="list --dates 1900-01-01:2100-01-01 --sum2 68" --quiet
Получаем:
1906-12-31: 19+06+12+31=68
1907-12-30: 19+07+12+30=68
1908-10-31: 19+08+10+31=68
1908-11-30: 19+08+11+30=68
1908-12-29: 19+08+12+29=68
1909-10-30: 19+09+10+30=68
1909-11-29: 19+09+11+29=68
1909-12-28: 19+09+12+28=68
1910-08-31: 19+10+08+31=68
1910-09-30: 19+10+09+30=68
1910-10-29: 19+10+10+29=68
1910-11-28: 19+10+11+28=68
1910-12-27: 19+10+12+27=68
1911-07-31: 19+11+07+31=68
1911-08-30: 19+11+08+30=68
1911-09-29: 19+11+09+29=68
1911-10-28: 19+11+10+28=68
1911-11-27: 19+11+11+27=68
1911-12-26: 19+11+12+26=68
1912-07-30: 19+12+07+30=68
1912-08-29: 19+12+08+29=68
1912-09-28: 19+12+09+28=68
1912-10-27: 19+12+10+27=68
1912-11-26: 19+12+11+26=68
1912-12-25: 19+12+12+25=68
1913-05-31: 19+13+05+31=68
1913-06-30: 19+13+06+30=68
1913-07-29: 19+13+07+29=68
1913-08-28: 19+13+08+28=68
1913-09-27: 19+13+09+27=68
1913-10-26: 19+13+10+26=68
1913-11-25: 19+13+11+25=68
1913-12-24: 19+13+12+24=68
1914-05-30: 19+14+05+30=68
1914-06-29: 19+14+06+29=68
1914-07-28: 19+14+07+28=68
1914-08-27: 19+14+08+27=68
1914-09-26: 19+14+09+26=68
1914-10-25: 19+14+10+25=68
1914-11-24: 19+14+11+24=68
1914-12-23: 19+14+12+23=68
1915-03-31: 19+15+03+31=68
1915-04-30: 19+15+04+30=68
1915-05-29: 19+15+05+29=68
1915-06-28: 19+15+06+28=68
1915-07-27: 19+15+07+27=68
1915-08-26: 19+15+08+26=68
1915-09-25: 19+15+09+25=68
1915-10-24: 19+15+10+24=68
1915-11-23: 19+15+11+23=68
1915-12-22: 19+15+12+22=68
1916-03-30: 19+16+03+30=68
1916-04-29: 19+16+04+29=68
1916-05-28: 19+16+05+28=68
1916-06-27: 19+16+06+27=68
1916-07-26: 19+16+07+26=68
1916-08-25: 19+16+08+25=68
1916-09-24: 19+16+09+24=68
1916-10-23: 19+16+10+23=68
1916-11-22: 19+16+11+22=68
1916-12-21: 19+16+12+21=68
1917-01-31: 19+17+01+31=68
1917-03-29: 19+17+03+29=68
1917-04-28: 19+17+04+28=68
1917-05-27: 19+17+05+27=68
1917-06-26: 19+17+06+26=68
1917-07-25: 19+17+07+25=68
1917-08-24: 19+17+08+24=68
1917-09-23: 19+17+09+23=68
1917-10-22: 19+17+10+22=68
1917-11-21: 19+17+11+21=68
1917-12-20: 19+17+12+20=68
1918-01-30: 19+18+01+30=68
1918-03-28: 19+18+03+28=68
1918-04-27: 19+18+04+27=68
1918-05-26: 19+18+05+26=68
1918-06-25: 19+18+06+25=68
1918-07-24: 19+18+07+24=68
1918-08-23: 19+18+08+23=68
1918-09-22: 19+18+09+22=68
1918-10-21: 19+18+10+21=68
1918-11-20: 19+18+11+20=68
1918-12-19: 19+18+12+19=68
1919-01-29: 19+19+01+29=68
1919-02-28: 19+19+02+28=68
1919-03-27: 19+19+03+27=68
1919-04-26: 19+19+04+26=68
1919-05-25: 19+19+05+25=68
1919-06-24: 19+19+06+24=68
1919-07-23: 19+19+07+23=68
1919-08-22: 19+19+08+22=68
1919-09-21: 19+19+09+21=68
1919-10-20: 19+19+10+20=68
1919-11-19: 19+19+11+19=68
1919-12-18: 19+19+12+18=68
1920-01-28: 19+20+01+28=68
1920-02-27: 19+20+02+27=68
1920-03-26: 19+20+03+26=68
1920-04-25: 19+20+04+25=68
1920-05-24: 19+20+05+24=68
1920-06-23: 19+20+06+23=68
1920-07-22: 19+20+07+22=68
1920-08-21: 19+20+08+21=68
1920-09-20: 19+20+09+20=68
1920-10-19: 19+20+10+19=68
1920-11-18: 19+20+11+18=68
1920-12-17: 19+20+12+17=68
1921-01-27: 19+21+01+27=68
1921-02-26: 19+21+02+26=68
1921-03-25: 19+21+03+25=68
1921-04-24: 19+21+04+24=68
1921-05-23: 19+21+05+23=68
1921-06-22: 19+21+06+22=68
1921-07-21: 19+21+07+21=68
1921-08-20: 19+21+08+20=68
1921-09-19: 19+21+09+19=68
1921-10-18: 19+21+10+18=68
1921-11-17: 19+21+11+17=68
1921-12-16: 19+21+12+16=68
1922-01-26: 19+22+01+26=68
1922-02-25: 19+22+02+25=68
1922-03-24: 19+22+03+24=68
1922-04-23: 19+22+04+23=68
1922-05-22: 19+22+05+22=68
1922-06-21: 19+22+06+21=68
1922-07-20: 19+22+07+20=68
1922-08-19: 19+22+08+19=68
1922-09-18: 19+22+09+18=68
1922-10-17: 19+22+10+17=68
1922-11-16: 19+22+11+16=68
1922-12-15: 19+22+12+15=68
1923-01-25: 19+23+01+25=68
1923-02-24: 19+23+02+24=68
1923-03-23: 19+23+03+23=68
1923-04-22: 19+23+04+22=68
1923-05-21: 19+23+05+21=68
1923-06-20: 19+23+06+20=68
1923-07-19: 19+23+07+19=68
1923-08-18: 19+23+08+18=68
1923-09-17: 19+23+09+17=68
1923-10-16: 19+23+10+16=68
1923-11-15: 19+23+11+15=68
1923-12-14: 19+23+12+14=68
1924-01-24: 19+24+01+24=68
1924-02-23: 19+24+02+23=68
1924-03-22: 19+24+03+22=68
1924-04-21: 19+24+04+21=68
1924-05-20: 19+24+05+20=68
1924-06-19: 19+24+06+19=68
1924-07-18: 19+24+07+18=68
1924-08-17: 19+24+08+17=68
1924-09-16: 19+24+09+16=68
1924-10-15: 19+24+10+15=68
1924-11-14: 19+24+11+14=68
1924-12-13: 19+24+12+13=68
1925-01-23: 19+25+01+23=68
1925-02-22: 19+25+02+22=68
1925-03-21: 19+25+03+21=68
1925-04-20: 19+25+04+20=68
1925-05-19: 19+25+05+19=68
1925-06-18: 19+25+06+18=68
1925-07-17: 19+25+07+17=68
1925-08-16: 19+25+08+16=68
1925-09-15: 19+25+09+15=68
1925-10-14: 19+25+10+14=68
1925-11-13: 19+25+11+13=68
1925-12-12: 19+25+12+12=68
1926-01-22: 19+26+01+22=68
1926-02-21: 19+26+02+21=68
1926-03-20: 19+26+03+20=68
1926-04-19: 19+26+04+19=68
1926-05-18: 19+26+05+18=68
1926-06-17: 19+26+06+17=68
1926-07-16: 19+26+07+16=68
1926-08-15: 19+26+08+15=68
1926-09-14: 19+26+09+14=68
1926-10-13: 19+26+10+13=68
1926-11-12: 19+26+11+12=68
1926-12-11: 19+26+12+11=68
1927-01-21: 19+27+01+21=68
1927-02-20: 19+27+02+20=68
1927-03-19: 19+27+03+19=68
1927-04-18: 19+27+04+18=68
1927-05-17: 19+27+05+17=68
1927-06-16: 19+27+06+16=68
1927-07-15: 19+27+07+15=68
1927-08-14: 19+27+08+14=68
1927-09-13: 19+27+09+13=68
1927-10-12: 19+27+10+12=68
1927-11-11: 19+27+11+11=68
1927-12-10: 19+27+12+10=68
1928-01-20: 19+28+01+20=68
1928-02-19: 19+28+02+19=68
1928-03-18: 19+28+03+18=68
1928-04-17: 19+28+04+17=68
1928-05-16: 19+28+05+16=68
1928-06-15: 19+28+06+15=68
1928-07-14: 19+28+07+14=68
1928-08-13: 19+28+08+13=68
1928-09-12: 19+28+09+12=68
1928-10-11: 19+28+10+11=68
1928-11-10: 19+28+11+10=68
1928-12-09: 19+28+12+09=68
1929-01-19: 19+29+01+19=68
1929-02-18: 19+29+02+18=68
1929-03-17: 19+29+03+17=68
1929-04-16: 19+29+04+16=68
1929-05-15: 19+29+05+15=68
1929-06-14: 19+29+06+14=68
1929-07-13: 19+29+07+13=68
1929-08-12: 19+29+08+12=68
1929-09-11: 19+29+09+11=68
1929-10-10: 19+29+10+10=68
1929-11-09: 19+29+11+09=68
1929-12-08: 19+29+12+08=68
1930-01-18: 19+30+01+18=68
1930-02-17: 19+30+02+17=68
1930-03-16: 19+30+03+16=68
1930-04-15: 19+30+04+15=68
1930-05-14: 19+30+05+14=68
1930-06-13: 19+30+06+13=68
1930-07-12: 19+30+07+12=68
1930-08-11: 19+30+08+11=68
1930-09-10: 19+30+09+10=68
1930-10-09: 19+30+10+09=68
1930-11-08: 19+30+11+08=68
1930-12-07: 19+30+12+07=68
1931-01-17: 19+31+01+17=68
1931-02-16: 19+31+02+16=68
1931-03-15: 19+31+03+15=68
1931-04-14: 19+31+04+14=68
1931-05-13: 19+31+05+13=68
1931-06-12: 19+31+06+12=68
1931-07-11: 19+31+07+11=68
1931-08-10: 19+31+08+10=68
1931-09-09: 19+31+09+09=68
1931-10-08: 19+31+10+08=68
1931-11-07: 19+31+11+07=68
1931-12-06: 19+31+12+06=68
1932-01-16: 19+32+01+16=68
1932-02-15: 19+32+02+15=68
1932-03-14: 19+32+03+14=68
1932-04-13: 19+32+04+13=68
1932-05-12: 19+32+05+12=68
1932-06-11: 19+32+06+11=68
1932-07-10: 19+32+07+10=68
1932-08-09: 19+32+08+09=68
1932-09-08: 19+32+09+08=68
1932-10-07: 19+32+10+07=68
1932-11-06: 19+32+11+06=68
1932-12-05: 19+32+12+05=68
1933-01-15: 19+33+01+15=68
1933-02-14: 19+33+02+14=68
1933-03-13: 19+33+03+13=68
1933-04-12: 19+33+04+12=68
1933-05-11: 19+33+05+11=68
1933-06-10: 19+33+06+10=68
1933-07-09: 19+33+07+09=68
1933-08-08: 19+33+08+08=68
1933-09-07: 19+33+09+07=68
1933-10-06: 19+33+10+06=68
1933-11-05: 19+33+11+05=68
1933-12-04: 19+33+12+04=68
1934-01-14: 19+34+01+14=68
1934-02-13: 19+34+02+13=68
1934-03-12: 19+34+03+12=68
1934-04-11: 19+34+04+11=68
1934-05-10: 19+34+05+10=68
1934-06-09: 19+34+06+09=68
1934-07-08: 19+34+07+08=68
1934-08-07: 19+34+08+07=68
1934-09-06: 19+34+09+06=68
1934-10-05: 19+34+10+05=68
1934-11-04: 19+34+11+04=68
1934-12-03: 19+34+12+03=68
1935-01-13: 19+35+01+13=68
1935-02-12: 19+35+02+12=68
1935-03-11: 19+35+03+11=68
1935-04-10: 19+35+04+10=68
1935-05-09: 19+35+05+09=68
1935-06-08: 19+35+06+08=68
1935-07-07: 19+35+07+07=68
1935-08-06: 19+35+08+06=68
1935-09-05: 19+35+09+05=68
1935-10-04: 19+35+10+04=68
1935-11-03: 19+35+11+03=68
1935-12-02: 19+35+12+02=68
1936-01-12: 19+36+01+12=68
1936-02-11: 19+36+02+11=68
1936-03-10: 19+36+03+10=68
1936-04-09: 19+36+04+09=68
1936-05-08: 19+36+05+08=68
1936-06-07: 19+36+06+07=68
1936-07-06: 19+36+07+06=68
1936-08-05: 19+36+08+05=68
1936-09-04: 19+36+09+04=68
1936-10-03: 19+36+10+03=68
1936-11-02: 19+36+11+02=68
1936-12-01: 19+36+12+01=68
1937-01-11: 19+37+01+11=68
1937-02-10: 19+37+02+10=68
1937-03-09: 19+37+03+09=68
1937-04-08: 19+37+04+08=68
1937-05-07: 19+37+05+07=68
1937-06-06: 19+37+06+06=68
1937-07-05: 19+37+07+05=68
1937-08-04: 19+37+08+04=68
1937-09-03: 19+37+09+03=68
1937-10-02: 19+37+10+02=68
1937-11-01: 19+37+11+01=68
1938-01-10: 19+38+01+10=68
1938-02-09: 19+38+02+09=68
1938-03-08: 19+38+03+08=68
1938-04-07: 19+38+04+07=68
1938-05-06: 19+38+05+06=68
1938-06-05: 19+38+06+05=68
1938-07-04: 19+38+07+04=68
1938-08-03: 19+38+08+03=68
1938-09-02: 19+38+09+02=68
1938-10-01: 19+38+10+01=68
1939-01-09: 19+39+01+09=68
1939-02-08: 19+39+02+08=68
1939-03-07: 19+39+03+07=68
1939-04-06: 19+39+04+06=68
1939-05-05: 19+39+05+05=68
1939-06-04: 19+39+06+04=68
1939-07-03: 19+39+07+03=68
1939-08-02: 19+39+08+02=68
1939-09-01: 19+39+09+01=68
1940-01-08: 19+40+01+08=68
1940-02-07: 19+40+02+07=68
1940-03-06: 19+40+03+06=68
1940-04-05: 19+40+04+05=68
1940-05-04: 19+40+05+04=68
1940-06-03: 19+40+06+03=68
1940-07-02: 19+40+07+02=68
1940-08-01: 19+40+08+01=68
1941-01-07: 19+41+01+07=68
1941-02-06: 19+41+02+06=68
1941-03-05: 19+41+03+05=68
1941-04-04: 19+41+04+04=68
1941-05-03: 19+41+05+03=68
1941-06-02: 19+41+06+02=68
1941-07-01: 19+41+07+01=68
1942-01-06: 19+42+01+06=68
1942-02-05: 19+42+02+05=68
1942-03-04: 19+42+03+04=68
1942-04-03: 19+42+04+03=68
1942-05-02: 19+42+05+02=68
1942-06-01: 19+42+06+01=68
1943-01-05: 19+43+01+05=68
1943-02-04: 19+43+02+04=68
1943-03-03: 19+43+03+03=68
1943-04-02: 19+43+04+02=68
1943-05-01: 19+43+05+01=68
1944-01-04: 19+44+01+04=68
1944-02-03: 19+44+02+03=68
1944-03-02: 19+44+03+02=68
1944-04-01: 19+44+04+01=68
1945-01-03: 19+45+01+03=68
1945-02-02: 19+45+02+02=68
1945-03-01: 19+45+03+01=68
1946-01-02: 19+46+01+02=68
1946-02-01: 19+46+02+01=68
1947-01-01: 19+47+01+01=68
2005-12-31: 20+05+12+31=68
2006-12-30: 20+06+12+30=68
2007-10-31: 20+07+10+31=68
2007-11-30: 20+07+11+30=68
2007-12-29: 20+07+12+29=68
2008-10-30: 20+08+10+30=68
2008-11-29: 20+08+11+29=68
2008-12-28: 20+08+12+28=68
2009-08-31: 20+09+08+31=68
2009-09-30: 20+09+09+30=68
2009-10-29: 20+09+10+29=68
2009-11-28: 20+09+11+28=68
2009-12-27: 20+09+12+27=68
2010-07-31: 20+10+07+31=68
2010-08-30: 20+10+08+30=68
2010-09-29: 20+10+09+29=68
2010-10-28: 20+10+10+28=68
2010-11-27: 20+10+11+27=68
2010-12-26: 20+10+12+26=68
2011-07-30: 20+11+07+30=68
2011-08-29: 20+11+08+29=68
2011-09-28: 20+11+09+28=68
2011-10-27: 20+11+10+27=68
2011-11-26: 20+11+11+26=68
2011-12-25: 20+11+12+25=68
2012-05-31: 20+12+05+31=68
2012-06-30: 20+12+06+30=68
2012-07-29: 20+12+07+29=68
2012-08-28: 20+12+08+28=68
2012-09-27: 20+12+09+27=68
2012-10-26: 20+12+10+26=68
2012-11-25: 20+12+11+25=68
2012-12-24: 20+12+12+24=68
2013-05-30: 20+13+05+30=68
2013-06-29: 20+13+06+29=68
2013-07-28: 20+13+07+28=68
2013-08-27: 20+13+08+27=68
2013-09-26: 20+13+09+26=68
2013-10-25: 20+13+10+25=68
2013-11-24: 20+13+11+24=68
2013-12-23: 20+13+12+23=68
2014-03-31: 20+14+03+31=68
2014-04-30: 20+14+04+30=68
2014-05-29: 20+14+05+29=68
2014-06-28: 20+14+06+28=68
2014-07-27: 20+14+07+27=68
2014-08-26: 20+14+08+26=68
2014-09-25: 20+14+09+25=68
2014-10-24: 20+14+10+24=68
2014-11-23: 20+14+11+23=68
2014-12-22: 20+14+12+22=68
2015-03-30: 20+15+03+30=68
2015-04-29: 20+15+04+29=68
2015-05-28: 20+15+05+28=68
2015-06-27: 20+15+06+27=68
2015-07-26: 20+15+07+26=68
2015-08-25: 20+15+08+25=68
2015-09-24: 20+15+09+24=68
2015-10-23: 20+15+10+23=68
2015-11-22: 20+15+11+22=68
2015-12-21: 20+15+12+21=68
2016-01-31: 20+16+01+31=68
2016-03-29: 20+16+03+29=68
2016-04-28: 20+16+04+28=68
2016-05-27: 20+16+05+27=68
2016-06-26: 20+16+06+26=68
2016-07-25: 20+16+07+25=68
2016-08-24: 20+16+08+24=68
2016-09-23: 20+16+09+23=68
2016-10-22: 20+16+10+22=68
2016-11-21: 20+16+11+21=68
2016-12-20: 20+16+12+20=68
2017-01-30: 20+17+01+30=68
2017-03-28: 20+17+03+28=68
2017-04-27: 20+17+04+27=68
2017-05-26: 20+17+05+26=68
2017-06-25: 20+17+06+25=68
2017-07-24: 20+17+07+24=68
2017-08-23: 20+17+08+23=68
2017-09-22: 20+17+09+22=68
2017-10-21: 20+17+10+21=68
2017-11-20: 20+17+11+20=68
2017-12-19: 20+17+12+19=68
2018-01-29: 20+18+01+29=68
2018-02-28: 20+18+02+28=68
2018-03-27: 20+18+03+27=68
2018-04-26: 20+18+04+26=68
2018-05-25: 20+18+05+25=68
2018-06-24: 20+18+06+24=68
2018-07-23: 20+18+07+23=68
2018-08-22: 20+18+08+22=68
2018-09-21: 20+18+09+21=68
2018-10-20: 20+18+10+20=68
2018-11-19: 20+18+11+19=68
2018-12-18: 20+18+12+18=68
2019-01-28: 20+19+01+28=68
2019-02-27: 20+19+02+27=68
2019-03-26: 20+19+03+26=68
2019-04-25: 20+19+04+25=68
2019-05-24: 20+19+05+24=68
2019-06-23: 20+19+06+23=68
2019-07-22: 20+19+07+22=68
2019-08-21: 20+19+08+21=68
2019-09-20: 20+19+09+20=68
2019-10-19: 20+19+10+19=68
2019-11-18: 20+19+11+18=68
2019-12-17: 20+19+12+17=68
2020-01-27: 20+20+01+27=68
2020-02-26: 20+20+02+26=68
2020-03-25: 20+20+03+25=68
2020-04-24: 20+20+04+24=68
2020-05-23: 20+20+05+23=68
2020-06-22: 20+20+06+22=68
2020-07-21: 20+20+07+21=68
2020-08-20: 20+20+08+20=68
2020-09-19: 20+20+09+19=68
2020-10-18: 20+20+10+18=68
2020-11-17: 20+20+11+17=68
2020-12-16: 20+20+12+16=68
2021-01-26: 20+21+01+26=68
2021-02-25: 20+21+02+25=68
2021-03-24: 20+21+03+24=68
2021-04-23: 20+21+04+23=68
2021-05-22: 20+21+05+22=68
2021-06-21: 20+21+06+21=68
2021-07-20: 20+21+07+20=68
2021-08-19: 20+21+08+19=68
2021-09-18: 20+21+09+18=68
2021-10-17: 20+21+10+17=68
2021-11-16: 20+21+11+16=68
2021-12-15: 20+21+12+15=68
2022-01-25: 20+22+01+25=68
2022-02-24: 20+22+02+24=68
2022-03-23: 20+22+03+23=68
2022-04-22: 20+22+04+22=68
2022-05-21: 20+22+05+21=68
2022-06-20: 20+22+06+20=68
2022-07-19: 20+22+07+19=68
2022-08-18: 20+22+08+18=68
2022-09-17: 20+22+09+17=68
2022-10-16: 20+22+10+16=68
2022-11-15: 20+22+11+15=68
2022-12-14: 20+22+12+14=68
2023-01-24: 20+23+01+24=68
2023-02-23: 20+23+02+23=68
2023-03-22: 20+23+03+22=68
2023-04-21: 20+23+04+21=68
2023-05-20: 20+23+05+20=68
2023-06-19: 20+23+06+19=68
2023-07-18: 20+23+07+18=68
2023-08-17: 20+23+08+17=68
2023-09-16: 20+23+09+16=68
2023-10-15: 20+23+10+15=68
2023-11-14: 20+23+11+14=68
2023-12-13: 20+23+12+13=68
2024-01-23: 20+24+01+23=68
2024-02-22: 20+24+02+22=68
2024-03-21: 20+24+03+21=68
2024-04-20: 20+24+04+20=68
2024-05-19: 20+24+05+19=68
2024-06-18: 20+24+06+18=68
2024-07-17: 20+24+07+17=68
2024-08-16: 20+24+08+16=68
2024-09-15: 20+24+09+15=68
2024-10-14: 20+24+10+14=68
2024-11-13: 20+24+11+13=68
2024-12-12: 20+24+12+12=68
2025-01-22: 20+25+01+22=68
2025-02-21: 20+25+02+21=68
2025-03-20: 20+25+03+20=68
2025-04-19: 20+25+04+19=68
2025-05-18: 20+25+05+18=68
2025-06-17: 20+25+06+17=68
2025-07-16: 20+25+07+16=68
2025-08-15: 20+25+08+15=68
2025-09-14: 20+25+09+14=68
2025-10-13: 20+25+10+13=68
2025-11-12: 20+25+11+12=68
2025-12-11: 20+25+12+11=68
2026-01-21: 20+26+01+21=68
2026-02-20: 20+26+02+20=68
2026-03-19: 20+26+03+19=68
2026-04-18: 20+26+04+18=68
2026-05-17: 20+26+05+17=68
2026-06-16: 20+26+06+16=68
2026-07-15: 20+26+07+15=68
2026-08-14: 20+26+08+14=68
2026-09-13: 20+26+09+13=68
2026-10-12: 20+26+10+12=68
2026-11-11: 20+26+11+11=68
2026-12-10: 20+26+12+10=68
2027-01-20: 20+27+01+20=68
2027-02-19: 20+27+02+19=68
2027-03-18: 20+27+03+18=68
2027-04-17: 20+27+04+17=68
2027-05-16: 20+27+05+16=68
2027-06-15: 20+27+06+15=68
2027-07-14: 20+27+07+14=68
2027-08-13: 20+27+08+13=68
2027-09-12: 20+27+09+12=68
2027-10-11: 20+27+10+11=68
2027-11-10: 20+27+11+10=68
2027-12-09: 20+27+12+09=68
2028-01-19: 20+28+01+19=68
2028-02-18: 20+28+02+18=68
2028-03-17: 20+28+03+17=68
2028-04-16: 20+28+04+16=68
2028-05-15: 20+28+05+15=68
2028-06-14: 20+28+06+14=68
2028-07-13: 20+28+07+13=68
2028-08-12: 20+28+08+12=68
2028-09-11: 20+28+09+11=68
2028-10-10: 20+28+10+10=68
2028-11-09: 20+28+11+09=68
2028-12-08: 20+28+12+08=68
2029-01-18: 20+29+01+18=68
2029-02-17: 20+29+02+17=68
2029-03-16: 20+29+03+16=68
2029-04-15: 20+29+04+15=68
2029-05-14: 20+29+05+14=68
2029-06-13: 20+29+06+13=68
2029-07-12: 20+29+07+12=68
2029-08-11: 20+29+08+11=68
2029-09-10: 20+29+09+10=68
2029-10-09: 20+29+10+09=68
2029-11-08: 20+29+11+08=68
2029-12-07: 20+29+12+07=68
2030-01-17: 20+30+01+17=68
2030-02-16: 20+30+02+16=68
2030-03-15: 20+30+03+15=68
2030-04-14: 20+30+04+14=68
2030-05-13: 20+30+05+13=68
2030-06-12: 20+30+06+12=68
2030-07-11: 20+30+07+11=68
2030-08-10: 20+30+08+10=68
2030-09-09: 20+30+09+09=68
2030-10-08: 20+30+10+08=68
2030-11-07: 20+30+11+07=68
2030-12-06: 20+30+12+06=68
2031-01-16: 20+31+01+16=68
2031-02-15: 20+31+02+15=68
2031-03-14: 20+31+03+14=68
2031-04-13: 20+31+04+13=68
2031-05-12: 20+31+05+12=68
2031-06-11: 20+31+06+11=68
2031-07-10: 20+31+07+10=68
2031-08-09: 20+31+08+09=68
2031-09-08: 20+31+09+08=68
2031-10-07: 20+31+10+07=68
2031-11-06: 20+31+11+06=68
2031-12-05: 20+31+12+05=68
2032-01-15: 20+32+01+15=68
2032-02-14: 20+32+02+14=68
2032-03-13: 20+32+03+13=68
2032-04-12: 20+32+04+12=68
2032-05-11: 20+32+05+11=68
2032-06-10: 20+32+06+10=68
2032-07-09: 20+32+07+09=68
2032-08-08: 20+32+08+08=68
2032-09-07: 20+32+09+07=68
2032-10-06: 20+32+10+06=68
2032-11-05: 20+32+11+05=68
2032-12-04: 20+32+12+04=68
2033-01-14: 20+33+01+14=68
2033-02-13: 20+33+02+13=68
2033-03-12: 20+33+03+12=68
2033-04-11: 20+33+04+11=68
2033-05-10: 20+33+05+10=68
2033-06-09: 20+33+06+09=68
2033-07-08: 20+33+07+08=68
2033-08-07: 20+33+08+07=68
2033-09-06: 20+33+09+06=68
2033-10-05: 20+33+10+05=68
2033-11-04: 20+33+11+04=68
2033-12-03: 20+33+12+03=68
2034-01-13: 20+34+01+13=68
2034-02-12: 20+34+02+12=68
2034-03-11: 20+34+03+11=68
2034-04-10: 20+34+04+10=68
2034-05-09: 20+34+05+09=68
2034-06-08: 20+34+06+08=68
2034-07-07: 20+34+07+07=68
2034-08-06: 20+34+08+06=68
2034-09-05: 20+34+09+05=68
2034-10-04: 20+34+10+04=68
2034-11-03: 20+34+11+03=68
2034-12-02: 20+34+12+02=68
2035-01-12: 20+35+01+12=68
2035-02-11: 20+35+02+11=68
2035-03-10: 20+35+03+10=68
2035-04-09: 20+35+04+09=68
2035-05-08: 20+35+05+08=68
2035-06-07: 20+35+06+07=68
2035-07-06: 20+35+07+06=68
2035-08-05: 20+35+08+05=68
2035-09-04: 20+35+09+04=68
2035-10-03: 20+35+10+03=68
2035-11-02: 20+35+11+02=68
2035-12-01: 20+35+12+01=68
2036-01-11: 20+36+01+11=68
2036-02-10: 20+36+02+10=68
2036-03-09: 20+36+03+09=68
2036-04-08: 20+36+04+08=68
2036-05-07: 20+36+05+07=68
2036-06-06: 20+36+06+06=68
2036-07-05: 20+36+07+05=68
2036-08-04: 20+36+08+04=68
2036-09-03: 20+36+09+03=68
2036-10-02: 20+36+10+02=68
2036-11-01: 20+36+11+01=68
2037-01-10: 20+37+01+10=68
2037-02-09: 20+37+02+09=68
2037-03-08: 20+37+03+08=68
2037-04-07: 20+37+04+07=68
2037-05-06: 20+37+05+06=68
2037-06-05: 20+37+06+05=68
2037-07-04: 20+37+07+04=68
2037-08-03: 20+37+08+03=68
2037-09-02: 20+37+09+02=68
2037-10-01: 20+37+10+01=68
2038-01-09: 20+38+01+09=68
2038-02-08: 20+38+02+08=68
2038-03-07: 20+38+03+07=68
2038-04-06: 20+38+04+06=68
2038-05-05: 20+38+05+05=68
2038-06-04: 20+38+06+04=68
2038-07-03: 20+38+07+03=68
2038-08-02: 20+38+08+02=68
2038-09-01: 20+38+09+01=68
2039-01-08: 20+39+01+08=68
2039-02-07: 20+39+02+07=68
2039-03-06: 20+39+03+06=68
2039-04-05: 20+39+04+05=68
2039-05-04: 20+39+05+04=68
2039-06-03: 20+39+06+03=68
2039-07-02: 20+39+07+02=68
2039-08-01: 20+39+08+01=68
2040-01-07: 20+40+01+07=68
2040-02-06: 20+40+02+06=68
2040-03-05: 20+40+03+05=68
2040-04-04: 20+40+04+04=68
2040-05-03: 20+40+05+03=68
2040-06-02: 20+40+06+02=68
2040-07-01: 20+40+07+01=68
2041-01-06: 20+41+01+06=68
2041-02-05: 20+41+02+05=68
2041-03-04: 20+41+03+04=68
2041-04-03: 20+41+04+03=68
2041-05-02: 20+41+05+02=68
2041-06-01: 20+41+06+01=68
2042-01-05: 20+42+01+05=68
2042-02-04: 20+42+02+04=68
2042-03-03: 20+42+03+03=68
2042-04-02: 20+42+04+02=68
2042-05-01: 20+42+05+01=68
2043-01-04: 20+43+01+04=68
2043-02-03: 20+43+02+03=68
2043-03-02: 20+43+03+02=68
2043-04-01: 20+43+04+01=68
2044-01-03: 20+44+01+03=68
2044-02-02: 20+44+02+02=68
2044-03-01: 20+44+03+01=68
2045-01-02: 20+45+01+02=68
2045-02-01: 20+45+02+01=68
2046-01-01: 20+46+01+01=68
А сколько же их за 200 лет всего?
$ gradle run --args="list --dates 1900-01-01:2100-01-01 --sum2 68" --quiet | wc -l
Получаем 730.
И бонусом ещё посмотрим распределение, сколько дат в какую сумму укладывается за эти же 200 лет:
$ gradle run --args="hist --dates 1900-01-01:2100-01-01 --sum two" --quiet
Получаем транспонированную гистограмму в текстовом виде:
001 : 000 |
002 : 000 |
003 : 000 |
004 : 000 |
005 : 000 |
006 : 000 |
007 : 000 |
008 : 000 |
009 : 000 |
010 : 000 |
011 : 000 |
012 : 000 |
013 : 000 |
014 : 000 |
015 : 000 |
016 : 000 |
017 : 000 |
018 : 000 |
019 : 000 |
020 : 000 |
021 : 001 | -
022 : 004 | -
023 : 009 | -
024 : 016 | -
025 : 025 | -
026 : 036 | -
027 : 049 | =-
028 : 064 | =-
029 : 081 | ==-
030 : 100 | ==-
031 : 121 | ===-
032 : 144 | ===-
033 : 168 | ====-
034 : 192 | =====-
035 : 216 | =====-
036 : 240 | ======-
037 : 264 | =======-
038 : 288 | =======-
039 : 312 | ========-
040 : 336 | =========-
041 : 360 | =========-
042 : 384 | ==========-
043 : 408 | ===========-
044 : 432 | ===========-
045 : 456 | ============-
046 : 480 | =============-
047 : 504 | =============-
048 : 528 | ==============-
049 : 552 | ===============-
050 : 575 | ===============-
051 : 598 | ================-
052 : 618 | ================-
053 : 638 | =================-
054 : 657 | =================-
055 : 673 | ==================-
056 : 686 | ==================-
057 : 698 | ===================-
058 : 710 | ===================-
059 : 718 | ===================-
060 : 723 | ===================-
061 : 727 | ===================-
062 : 730 | ===================-
063 : 731 | ====================-
064 : 730 | ===================-
065 : 730 | ===================-
066 : 731 | ====================-
067 : 731 | ====================-
068 : 730 | ===================-
069 : 730 | ===================-
070 : 731 | ====================-
071 : 731 | ====================-
072 : 730 | ===================-
073 : 730 | ===================-
074 : 731 | ====================-
075 : 731 | ====================-
076 : 730 | ===================-
077 : 730 | ===================-
078 : 731 | ====================-
079 : 731 | ====================-
080 : 730 | ===================-
081 : 730 | ===================-
082 : 731 | ====================-
083 : 731 | ====================-
084 : 730 | ===================-
085 : 730 | ===================-
086 : 731 | ====================-
087 : 731 | ====================-
088 : 730 | ===================-
089 : 730 | ===================-
090 : 731 | ====================-
091 : 731 | ====================-
092 : 730 | ===================-
093 : 730 | ===================-
094 : 731 | ====================-
095 : 731 | ====================-
096 : 730 | ===================-
097 : 730 | ===================-
098 : 731 | ====================-
099 : 731 | ====================-
100 : 730 | ===================-
101 : 730 | ===================-
102 : 731 | ====================-
103 : 731 | ====================-
104 : 730 | ===================-
105 : 730 | ===================-
106 : 731 | ====================-
107 : 731 | ====================-
108 : 730 | ===================-
109 : 730 | ===================-
110 : 731 | ====================-
111 : 731 | ====================-
112 : 730 | ===================-
113 : 730 | ===================-
114 : 731 | ====================-
115 : 731 | ====================-
116 : 730 | ===================-
117 : 730 | ===================-
118 : 731 | ====================-
119 : 731 | ====================-
120 : 730 | ===================-
121 : 729 | ===================-
122 : 727 | ===================-
123 : 722 | ===================-
124 : 714 | ===================-
125 : 705 | ===================-
126 : 695 | ===================-
127 : 682 | ==================-
128 : 666 | ==================-
129 : 649 | =================-
130 : 631 | =================-
131 : 610 | ================-
132 : 586 | ================-
133 : 562 | ===============-
134 : 539 | ==============-
135 : 515 | ==============-
136 : 490 | =============-
137 : 466 | ============-
138 : 443 | ============-
139 : 419 | ===========-
140 : 394 | ==========-
141 : 370 | ==========-
142 : 347 | =========-
143 : 323 | ========-
144 : 298 | ========-
145 : 274 | =======-
146 : 251 | ======-
147 : 227 | ======-
148 : 202 | =====-
149 : 178 | ====-
150 : 155 | ====-
151 : 133 | ===-
152 : 112 | ===-
153 : 092 | ==-
154 : 074 | ==-
155 : 058 | =-
156 : 044 | =-
157 : 032 | -
158 : 021 | -
159 : 013 | -
160 : 007 | -
161 : 003 | -
Выводы
68 - вполне заурядное число. Распределение достаточно равномерное. Бонусом, имею мини-проект, который может пригодиться при устройстве на работу. Да и на память себе, а то может на Scala уже не будет работы.