A116639 Numbers n such that 13^n == 15 (mod n).

1, 2, 14, 22, 1582, 11266, 52766, 76202, 100562, 494371, 641141, 1698494, 66593158, 469296521, 10917186079, 12062558662, 4928050067287, 5315948729617, 29841213777637, 113215787397262, 778590786358582, 787324867879046

Offset: 1

Author

Zak Seidov, Feb 19 2006

Keywords

• nonn

Comments

No other terms below 10^15. Some large terms: 6991413003775539262, 2360895769139218729155198091. - Max Alekseyev, Oct 15 2016

Crossrefs

Cf. A116609, A116611, A116620, A116621, A116622, A116629, A116630, A116631, A116632, A116636, A116638.

Programs

Mathematica

Select[Range[25000000],PowerMod[13,#,# ]==15&] (* Harvey P. Dale, Feb 03 2009 *)

Extensions

One more term from Harvey P. Dale, Feb 03 2009

Edited by Max Alekseyev, Sep 19 2009

a(14)-a(22) from Max Alekseyev, May 04 2010, Apr 29 2014, Oct 15 2016