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 A139673 #8 Mar 09 2020 20:55:01 %S A139673 1,232,66178,24243520,11234051976,6549149852112,4762109992158288, %T A139673 4274712091685443584,4686484162304929219950,6209619146419137708859600, %U A139673 9845751579221258486943505348,18509102695712474753650903363840,40904306737052771732376660591663712 %N A139673 Number of n X n symmetric binary matrices with all row sums 6. %H A139673 Andrew Howroyd, <a href="/A139673/b139673.txt">Table of n, a(n) for n = 6..25</a> %Y A139673 Column k=6 of A333157 and row 6 of A188448. %K A139673 nonn %O A139673 6,2 %A A139673 _R. H. Hardin_, Jun 12 2008 %E A139673 Terms a(13) and beyond from _Andrew Howroyd_, Mar 09 2020