A128397 Numbers k such that k^2 divides 17^k-1.

1, 2, 4, 6, 8, 12, 16, 18, 20, 24, 36, 40, 42, 48, 60, 72, 78, 80, 84, 116, 120, 126, 144, 156, 168, 180, 220, 232, 234, 240, 252, 312, 336, 342, 348, 360, 420, 440, 464, 468, 504, 546, 580, 624, 660, 684, 696, 720, 780, 840, 880, 936, 1008, 1044, 1092, 1160

Offset

1,2

Comments

The first 9 numbers (and many more) which are a multiple of their digital sum in all bases from 2 through 16 (A218087), are members of this sequence, and also of A177917. - M. F. Hasler, Oct 22 2012

Links

Table of n, a(n) for n=1..56.

Prog

(PARI) is_A128397(n)=Mod(17, n^2)^n==1  \\ M. F. Hasler, Oct 22 2012

Crossrefs

Cf. A127103, A127104, A127105, A127106, A127107, A127102, A127101, A127100, A127092, A128405, A128393, A128394, A128395, A128396, A128398, A128399, A128400, A128401, A128402, A128403, A128404.

Cf. A177917.

Sequence in context: A067712 A060765 A140110 * A120383 A324842 A055932

Adjacent sequences: A128394 A128395 A128396 * A128398 A128399 A128400

Keyword

nonn,less

Author

Alexander Adamchuk, Mar 01 2007

Status

approved