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

Author

Alexander Adamchuk, Mar 01 2007

Keywords

• nonn
• less

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

• Amiram Eldar, Table of n, a(n) for n = 1..10000

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.

Programs

PARI

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