A045589 Numbers k that divide 10^k + 3^k.
1, 13, 169, 1703, 2197, 22139, 28561, 76739, 223093, 287807, 371293, 447889, 994747, 997607, 2399293, 2900209, 3741491, 4826809, 5802121, 5822557, 10052809, 12931711, 12968891, 29225183, 31190809, 37702717, 48639383, 58673459, 62748517, 75427573, 75693241, 117794807
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..71
Crossrefs
Cf. A245806.
Programs
-
Mathematica
Select[Range[10^5], Divisible[PowerMod[10, #, #] + PowerMod[3, #, #], #] &] (* Amiram Eldar, Oct 23 2021 *)
Extensions
a(28)-a(32) from Amiram Eldar, Oct 23 2021