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A177906
Numbers k such that k^3 divides 6^(k^2) - 1.
0
1, 5, 1555, 9673655, 24181805, 90993505, 200928005, 28298980055, 36850702555, 62488609555, 141377087255, 150435008905, 367279622065, 2256331679135, 7521049172905, 18802586659555, 24599612913355, 54706615318945
OFFSET
1,2
COMMENTS
5 divides a(n) for n > 1.
Prime divisors of a(n) in order of their appearance are {5, 311, 6221, 15551, 18198701, 40185601, ...}.
From there on, the list is no longer increasing; it continues with 23698201, 90917741, 236192683, 93307, 311021, ... - M. F. Hasler, Oct 21 2012
PROG
(PARI) is_A177906(n)=Mod(6, n^3)^(n^2)==1 \\ M. F. Hasler, Oct 21 2012
CROSSREFS
Cf. A014946 (k divides 6^k-1), A127106 (k^2 divides 6^k-1).
Sequence in context: A014377 A165628 A119747 * A127106 A165877 A366830
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, May 16 2010
EXTENSIONS
More terms from Max Alekseyev, Oct 02 2010
STATUS
approved