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A045580 Numbers k that divide 7^k + 2^k. 1
1, 3, 9, 27, 39, 81, 117, 171, 243, 351, 507, 513, 729, 1053, 1521, 1539, 2187, 2223, 3081, 3159, 3249, 4563, 4617, 5109, 6123, 6561, 6591, 6669, 9243, 9477, 9747, 13689, 13851, 15327, 18153, 18369, 19683, 19773, 20007, 27729, 28431, 28899, 29241, 39159, 40053 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..2000

MATHEMATICA

Select[Range[30000], Divisible[PowerMod[2, #, #] + PowerMod[7, #, #], #] &] (* Amiram Eldar, Oct 23 2021 *)

CROSSREFS

Cf. A074602.

Sequence in context: A027889 A018766 A036126 * A070361 A056024 A116475

Adjacent sequences:  A045577 A045578 A045579 * A045581 A045582 A045583

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified January 27 09:44 EST 2022. Contains 350607 sequences. (Running on oeis4.)