

A015921


Positive integers n such that 2^n == 4 (mod n).


16



1, 2, 4, 6, 10, 12, 14, 22, 26, 30, 34, 38, 46, 58, 62, 74, 82, 86, 94, 106, 118, 122, 132, 134, 142, 146, 158, 166, 170, 178, 182, 194, 202, 206, 214, 218, 226, 254, 262, 274, 278, 298, 302, 314, 326, 334, 346, 358, 362, 372, 382, 386, 394, 398, 422, 446
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OFFSET

1,2


COMMENTS

Odd terms are given by A173572.
For all m, 2^A050259(m)1 belongs to this sequence.


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000
OEIS Wiki, 2^n mod n


MATHEMATICA

Select[Range[500], PowerMod[2, #, #] == 4 &] (* Alonso del Arte, Jul 07 2011 *)


CROSSREFS

Contains A050990 as a subsequence.
Cf. A015910, A173572.
Sequence in context: A301646 A024892 A087136 * A232964 A132631 A248614
Adjacent sequences: A015918 A015919 A015920 * A015922 A015923 A015924


KEYWORD

nonn


AUTHOR

Robert G. Wilson v


EXTENSIONS

Edited and terms 1,2,4 prepended by Max Alekseyev, Jul 29 2011


STATUS

approved



