OFFSET
1,2
COMMENTS
Numbers k such that k | A002315(k).
EXAMPLE
7 is a term since A002315(7) = 275807 = 7 * 39401 is divisible by 7.
MATHEMATICA
seq[kmax_] := Module[{nsw0 = 1, nsw1 = 7, nsw2, s = {1}}, Do[nsw2 = 6*nsw1 - nsw0; If[Divisible[nsw2, k], AppendTo[s, k]]; nsw0 = nsw1; nsw1 = nsw2, {k, 2, kmax}]; s]; seq[52000]
PROG
(PARI) lista(kmax) = {my(nsw0 = 1, nsw1 = 7, nsw2); print1("1, "); for(k = 2, kmax, nsw2 = 6*nsw1 - nsw0; if(!(nsw2 % k), print1(k, ", ")); nsw0 = nsw1; nsw1 = nsw2); }
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, May 17 2024
STATUS
approved