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 A328138 #25 Dec 27 2024 22:34:53 %S A328138 1,17,803,1241,20264753,28214180783393,228454543831049 %N A328138 Numbers m that divide 9^m + 8. %C A328138 Conjecture: For n > 1, k^n == 1-k (mod n) has an infinite number of positive solutions. %C A328138 No term can be a multiple of 2, 3, 5, 7, or 13. Also 4879573990210017348077958628152400091281634488825721395187 is a term. - _Giovanni Resta_, Oct 07 2019 %C A328138 Also 6788776064693081883870036833 is a term. - _Max Alekseyev_, Dec 27 2024 %F A328138 a(n) > 15n for large enough n. (Surely the sequence grows superlinearly, but I can't prove it.) - _Charles R Greathouse IV_, Dec 27 2024 %o A328138 (Magma) [1] cat [n: n in [1..10^8] | Modexp(9, n, n) + 8 eq n]; %o A328138 (PARI) isok(n) = Mod(9, n)^n==-8; \\ _Michel Marcus_, Oct 05 2019 %Y A328138 Subsequence of A008364. %Y A328138 Solutions to k^m == k-1 (mod m): 1 (k = 1), A006521 (k = 2), A015973 (k = 3), A327840 (k = 4), A123047 (k = 5), A327943 (k = 6), A328033 (k = 7), A327468 (k = 8), this sequence (k = 9). %Y A328138 Cf. A253212 (9^n + 8). %K A328138 nonn,more %O A328138 1,2 %A A328138 _Juri-Stepan Gerasimov_, Oct 04 2019 %E A328138 a(7) from _Giovanni Resta_ confirmed and a(6) added by _Max Alekseyev_, Dec 27 2024