A116638 Positive integers n such that 13^n == 11 (mod n).

1, 2, 158, 301823, 1851103, 8616098, 60528467, 1087582634, 1628818307, 16205558969

Offset: 1

Author

Zak Seidov, Feb 19 2006

Keywords

• more
• nonn

Comments

No other terms below 10^15. - Max Alekseyev, Nov 07 2018

Large terms: 38763675625170712166, 527929122195463909516681113715859203.

Crossrefs

Solutions to 13^n == k (mod n): A001022 (k=0), A015963 (k=-1), A116621 (k=1), A116622 (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), A295532 (k=8), A116636 (k=9), A116620 (k=10), this sequence (k=11), A116639 (k=15).

Cf. A116609.

Programs

Mathematica

Join[{1, 2}, Select[Range[1, 9000], Mod[13^#, #] == 11 &]] (* G. C. Greubel, Nov 20 2017 *)
Join[{1, 2}, Select[Range[10000000], PowerMod[13, #, #] == 11 &]] (* Robert Price, Apr 10 2020 *)

Extensions

More terms from Ryan Propper, Jan 11 2008

Edited by Max Alekseyev, May 04 2010