

A129497


Composite numbers n such that 7^n (mod n) is a power of 7 greater than 1.


5



14, 21, 25, 42, 50, 56, 58, 62, 70, 74, 82, 84, 86, 94, 98, 105, 106, 112, 118, 122, 132, 133, 134, 142, 146, 147, 150, 152, 158, 166, 168, 178, 182, 194, 196, 202, 206, 210, 214, 218, 226, 231, 254, 262, 266, 274, 278, 294, 298, 301, 302, 314, 325, 326, 334
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OFFSET

1,1


COMMENTS

Complement of composite numbers: 4, 6, 8, 9, 10, 12, 15, 16, 18, 20, 22, 24, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 44, 45, 46, 48, 49, 51, 52, 54, 55,..  R. J. Mathar, May 16 2008


LINKS

Table of n, a(n) for n=1..55.


EXAMPLE

58 is a member of the sequence since 7^58 (mod 58) == 49.


MATHEMATICA

Select[Range@ 335, IntegerQ@ Log[7, PowerMod[7, #, # ]] &]


CROSSREFS

Cf. A036236, A129492, A129493, A129494, A129495, A129496.
Sequence in context: A162780 A002410 A108606 * A255742 A093994 A114985
Adjacent sequences: A129494 A129495 A129496 * A129498 A129499 A129500


KEYWORD

easy,nonn


AUTHOR

Robert G. Wilson v, Apr 17 2007


EXTENSIONS

Corrected and edited by R. J. Mathar, May 16 2008


STATUS

approved



