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A126662 Numbers n such that 2^(n(n-1)) == 8 mod n. 1
28, 292, 553, 5026, 7519, 20062, 50888, 57337, 126532, 337372, 518161, 555448, 757156, 811687, 849583, 1518076, 3623809, 4529623, 6752431, 6908068, 6909961, 7826888, 9568183, 13594936, 16113217, 20766748, 21596722, 28534984, 34462456 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Related to A127931.

Up to 10^9, there are 55 terms (21 odd and 34 even numbers). All except two, 50888 and 7826888, are congruent to 1 mod 3 and none are congruent to 0 mod 3. Is the sequence infinite?

Terms so far are == {1, 4, 7, 8, 10} (mod 12) or {1, 4, 7, 8, 13, 16, 19, 22, 28} (mod 30) and none are == +/-3 (mod 8) nor == 5 (mod 10). - Robert G. Wilson v, Feb 12 2007

LINKS

Zak Seidov and Robert G. Wilson v, Table of n, a(n) for n = 1..68

MATHEMATICA

lst = {}; n = 3; While[n < 10000000000, If[PowerMod[2, n(n - 1), n] == 8, AppendTo[lst, n]; Print@n]; n++ ]; lst (* Robert G. Wilson v, Feb 11 2007 *)

CROSSREFS

Cf. A127931.

Sequence in context: A241621 A027781 A219626 * A156711 A107942 A219172

Adjacent sequences:  A126659 A126660 A126661 * A126663 A126664 A126665

KEYWORD

nonn

AUTHOR

Zak Seidov, Feb 10 2007

STATUS

approved

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Last modified August 26 05:50 EDT 2019. Contains 326330 sequences. (Running on oeis4.)