a(n) is the smallest even k >= 2 such that the first n multiples of k have the same sum of digits, but (n + 1)*k has a different one. a(n) = 0 if no such k exists.
A237994
a(n) is the smallest even k >= 2 such that the first n multiples of k have the same sum of digits, but (n + 1)*k has a different one. a(n) = 0 if no such k exists.
Terms
- a(0) =2a(1) =126a(2) =72a(3) =486a(4) =108a(5) =54a(6) =36a(7) =2772a(8) =0a(9) =18a(10) =918a(11) =2376a(12) =1782a(13) =34650a(14) =1728a(15) =1584a(16) =1386a(17) =8910a(18) =0a(19) =1188a(20) =95904a(21) =6930a(22) =87912a(23) =479502a(24) =81918a(25) =75924a(26) =73926a(27) =792a(28) =0a(29) =71928
External references
- oeis: A237994