A129496 Composite numbers k such that 6^k (mod k) is a power of 6 greater than 1.

10, 15, 21, 30, 35, 38, 42, 45, 46, 58, 60, 62, 70, 74, 82, 84, 86, 90, 94, 105, 106, 118, 122, 126, 132, 134, 140, 142, 146, 158, 166, 178, 180, 182, 185, 190, 194, 202, 206, 210, 214, 215, 217, 218, 219, 222, 226, 228, 231, 237, 249, 252, 254, 258, 259, 262

Offset: 1

Author

Robert G. Wilson v, Apr 17 2007

Keywords

• easy
• nonn

Examples

			38 is a member of the sequence since 6^38 (mod 38) == 36.
		

Links

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

Crossrefs

Cf. A036236, A129492, A129493, A129494, A129495, A129497.

Programs

Mathematica

Select[Range@ 266, (p = PowerMod[6, #, #]) > 1 && IntegerQ@ Log[6, p] && CompositeQ[#] &] (* corrected by Amiram Eldar, Jul 24 2021 *)