This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A295532 #8 Apr 10 2020 22:49:34
%S A295532 1,5,371285,3957661,70348567451,42831939409247
%N A295532 Positive integers n such that 13^n == 8 (mod n).
%C A295532 No other terms below 10^15.
%t A295532 Join[{1, 5}, Select[Range[4000000], PowerMod[13, #, #] == 8 &]] (* _Robert Price_, Apr 10 2020 *)
%Y A295532 Cf. A116609, A127821, A015922, A277630.
%Y A295532 Sequences 13^n == k (mod n): A116621 (k=1), A116622 (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), this sequence (k=8), A116636 (k=9), A116620 (k=10), A116638 (k=11), A116639 (k=15).
%K A295532 nonn,hard,more
%O A295532 1,2
%A A295532 _Max Alekseyev_, Nov 23 2017