A014869 Numbers k that divide s(k), where s(1)=1, s(j)=19*s(j-1)+j.

1, 3, 9, 19, 27, 57, 81, 171, 243, 381, 513, 729, 1143, 1539, 2187, 3429, 4617, 4707, 6561, 7239, 10287, 13053, 13149, 13851, 14121, 19683, 21717, 30861, 39159, 39447, 41553, 42363, 48387, 59049, 65151, 89433, 92583, 117477, 118341, 124659, 127089, 145161, 177147

Offset: 1

Author

N. J. A. Sloane, Olivier Gérard

Keywords

• nonn

Crossrefs

s(n) = A014903(n).

Programs

Mathematica

nxt[{n_,a_}]:={n+1,19a+n+1}; Transpose[Select[NestList[nxt,{1,1},70000], Divisible[Last[#],First[#]]&]][[1]] (* Harvey P. Dale, Jan 21 2015 *)

PARI

lista(nn) = my(s); for(k=1, nn, s=19*s+k; if(s%k==0, print1(k, ", "))); \\ Jinyuan Wang, Aug 08 2021

Extensions

More terms from Jinyuan Wang, Aug 08 2021