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 A246493 #8 Sep 06 2014 00:19:47 %S A246493 3,7,19,47,243,719,1439,2879,19683,59049,177147,531441,1594323,4782969 %N A246493 Smallest k such that 5^^n is not congruent to 5^^(n-1) mod k, where 5^^n denotes the power tower 5^5^...^5 (in which 5 appears n times). %C A246493 For general remarks regarding sequences of this type, see A246491. %o A246493 (Sage, cython) Use linked source from A246491 with this command: find_k_values(5,1,1) %Y A246493 Cf. A027763, A246491, A246492, A246494, A246495, A246496, A246497 %K A246493 nonn,more %O A246493 1,1 %A A246493 _Wayne VanWeerthuizen_, Aug 27 2014