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A126662
Numbers k such that 2^(k(k-1)) == 8 (mod k).
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
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
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 10 2007
STATUS
approved