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A045596
Numbers k that divide 7^k + 5^k.
1
1, 2, 3, 9, 27, 39, 74, 81, 117, 243, 351, 507, 729, 1053, 1521, 2187, 2738, 3081, 3159, 4563, 6123, 6561, 6591, 9243, 9477, 12207, 13689, 18369, 19683, 19773, 27729, 28431, 36621, 40053, 41067, 43882, 55107, 59049, 59319, 79599, 83187, 85293
OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..141 (* All terms up to 10^7. *)
MATHEMATICA
Select[Range[86000], Mod[PowerMod[7, #, #]+PowerMod[5, #, #], #]==0&] (* Harvey P. Dale, Aug 02 2023 *)
CROSSREFS
Cf. A074616.
Sequence in context: A177928 A057231 A178028 * A057299 A057296 A057248
KEYWORD
nonn
STATUS
approved