A033983 Integers n such that 2^n == 15 (mod n).

1, 13, 481, 44669, 1237231339, 1546675117, 62823773963, 284876771881, 1119485807557, 26598440989093

Offset: 1

Author

Joe K. Crump (joecr(AT)carolina.rr.com)

Keywords

• nonn
• more

Comments

No other terms below 10^14.

Links

• Joe K. Crump, 2^n mod n
• OEIS Wiki, 2^n mod n

Crossrefs

Cf. A125000, A124974, A033982, A033981, A050259, A124977, A124965, A015911, A015910.

Cf. A015910, A015911, A033981, A050259, A124965, A124974, A124977, A015910, A015911, A033982, A125000.

Programs

Mathematica

m = 15; Join[Select[Range[m], Divisible[2^# - m, #] &],
Select[Range[m + 1, 10^3], PowerMod[2, #, #] == m &]] (* Robert Price, Oct 08 2018 *)

Extensions

One more term from Joe K. Crump (joecr(AT)carolina.rr.com), Jun 20 2000

Edited by N. J. A. Sloane, Jul 03 2008 at the suggestion of R. J. Mathar

Terms 1, 13 prepended by Max Alekseyev, May 18 2011

a(10) from Max Alekseyev, Dec 15 2013