OFFSET
1,2
COMMENTS
From Robert Israel, Oct 07 2019: (Start)
Numbers k such that 144*k divides 1-(1-12*k)*13^k.
Contains all powers of 3 (A000244). (End)
MAPLE
filter:= proc(n) (1 - (1-12*n)*13 &^ n) mod (144*n) = 0 end proc:
select(filter, [$1..10^6]); # Robert Israel, Oct 07 2019
MATHEMATICA
s[1]=1; s[n_]:=s[n]=s[n-1]+n*13^(n-1); Select[Range[1000], Divisible[s[#], #] &] (* Amiram Eldar, Nov 23 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Sean A. Irvine, Nov 23 2018
STATUS
approved