a(n) is the smallest positive k such that the digit sums of k and k + 1 are both divisible by n, or -1 if no such pair exists.
A378119
a(n) is the smallest positive k such that the digit sums of k and k + 1 are both divisible by n, or -1 if no such pair exists.
Terms
- a(0) =1a(1) =19a(2) =-1a(3) =39a(4) =49999a(5) =-1a(6) =69999a(7) =79a(8) =-1a(9) =18999999999a(10) =2899999a(11) =-1a(12) =48999a(14) =-1a(15) =78999999999a(16) =8899a(17) =-1a(19) =298999999999a(20) =-1a(21) =49899999a(23) =-1a(25) =898999a(26) =-1a(29) =-1
External references
- oeis: A378119