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 A119009 #6 Jun 18 2025 16:59:45 %S A119009 1,4,22,286,5126,190096,9477868,923926396,118222774300 %N A119009 Number of n X n real symmetric (0,1)-matrices with permanent = 1. %Y A119009 Cf. A089482, A118986, A118989, A118991, A119008. %K A119009 nonn,more %O A119009 1,2 %A A119009 _Giovanni Resta_, May 08 2006 %E A119009 a(8)-a(9) from _Max Alekseyev_, Jun 18 2025