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 A377026 #8 Oct 18 2024 18:00:01 %S A377026 1,3,9,171,3249,97641,1855179,29884473,55753011,567804987,892145817, %T A377026 1059307209 %N A377026 Numbers k such that 2^(2^k+1) == -1 (mod k^2). %C A377026 It seems that these are cubefree terms of A006521. %Y A377026 Subsequence of A006521. %K A377026 nonn,more %O A377026 1,2 %A A377026 _Thomas Ordowski_, Oct 13 2024