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 A118995 #10 Jun 19 2025 00:24:03 %S A118995 1,4,32,592,11904,1192384,134217728,41896879104,16885168208896 %N A118995 Number of real n X n symmetric (+1,-1) matrices with positive permanent. %F A118995 a(n) = A118993(n) - A118999(n). For odd n, a(n) = A118999(n) = A118993(n)/2. - _Max Alekseyev_, Jun 18 2025 %Y A118995 Cf. A086900, A118988, A118999, A118993, A118994, A118999, A119001, A119010. %K A118995 nonn,more %O A118995 1,2 %A A118995 _Giovanni Resta_, May 08 2006 %E A118995 a(8)-a(9) from _Max Alekseyev_, Jun 18 2025