A015924 Positive integers n such that 2^n == 16 (mod n).

1, 2, 4, 6, 7, 8, 12, 16, 20, 24, 28, 40, 44, 48, 52, 60, 68, 76, 80, 92, 112, 116, 120, 124, 148, 154, 164, 172, 188, 204, 208, 212, 236, 240, 244, 264, 268, 280, 284, 292, 316, 332, 340, 356, 364, 388, 404, 412, 428, 436, 452, 508, 520, 524, 548, 556, 596

Offset: 1

Author

Robert G. Wilson v

Keywords

• nonn

Comments

Odd terms are given by A033984.

For all m, 2^A128121(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

Crossrefs

Contains A050992 as a subsequence.

Cf. A033984, A173138.

Programs

Mathematica

Select[Range[1000], Mod[2^# - 2^4, #] == 0 &] (* T. D. Noe, Aug 17 2012 *)
Join[{1,2,4,6,7,8,12,16},Select[Range[600],PowerMod[2,#,#]==16&]] (* Harvey P. Dale, Dec 03 2021 *)

Extensions

Edited and terms 1,2,4,6,7,8,12,16 prepended by Max Alekseyev, Jul 29 2011