This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A014861 #16 Aug 08 2021 11:34:01 %S A014861 1,3,9,13,27,39,81,117,183,243,351,549,689,729,1053,1647,2067,2187, %T A014861 2379,3081,3159,4941,6201,6561,7137,9243,9477,11163,14823,18603,19683, %U A014861 21411,27729,28431,33489,36517,42627,44469,55809,59049,64233,67161,73723,83187,85293 %N A014861 Numbers k that divide s(k), where s(1)=1, s(j)=13*s(j-1)+j. %o A014861 (PARI) lista(nn) = my(s); for(k=1, nn, s=13*s+k; if(s%k==0, print1(k, ", "))); \\ _Jinyuan Wang_, Aug 08 2021 %Y A014861 s(n) = A014896(n). %K A014861 nonn %O A014861 1,2 %A A014861 _N. J. A. Sloane_, _Olivier Gérard_ %E A014861 More terms from _Jinyuan Wang_, Aug 08 2021