%I #10 Nov 09 2018 07:58:58
%S 1,5805311,392908759,399614833907,2674764845549,21997277871211,
%T 67146783889057
%N Positive integers n such that 13^n == 14 (mod n).
%C No other terms below 10^15.
%o (PARI) is(n) = Mod(13, n)^n==14; \\ _Felix Fröhlich_, Nov 08 2018
%Y 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), A116638 (k=11), A321364 (k=12), this sequence (k=14), A116639 (k=15).
%Y Cf. A116609, A127821, A128149, A128172.
%K nonn,more
%O 1,2
%A _Max Alekseyev_, Nov 08 2018