A128393 - OEIS

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A128393

Numbers k such that k^2 divides 13^k - 1.

1, 2, 3, 4, 6, 12, 14, 20, 28, 42, 60, 68, 84, 140, 183, 204, 220, 340, 366, 406, 420, 476, 660, 732, 812, 942, 1020, 1218, 1428, 1540, 1806, 1860, 1884, 2380, 2436, 2562, 3612, 3660, 3740, 4060, 4620, 5060, 5124, 6594, 7004, 7140, 8420, 9420, 9940, 11220

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OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..500

MATHEMATICA

Join[{1}, Select[Range[12000], PowerMod[13, #, #^2]==1&]] (* Harvey P. Dale, Sep 05 2012 *)

CROSSREFS

Cf. A127103, A127104, A127105, A127106, A127107, A127102, A127101, A127100, A127092, A128405, A128394, A128395, A128396, A128397, A128398, A128399, A128400, A128401, A128402, A128403, A128404.

Sequence in context: A039038 A034293 A136291 * A368988 A057919 A102250

Adjacent sequences: A128390 A128391 A128392 * A128394 A128395 A128396

KEYWORD

nonn,less

AUTHOR

Alexander Adamchuk, Mar 01 2007

STATUS

approved