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 A261815 #10 Nov 26 2015 08:50:45 %S A261815 1,0,72,549504,4632344409600 %N A261815 Total number of semimagic squares of order n that can be formed from the numbers 1, ..., n^2. %H A261815 Wikipedia, <a href="https://en.wikipedia.org/wiki/Magic_graph">Magic graph</a> %H A261815 <a href="/index/Mag#magic">Index entries for sequences related to magic squares</a> %F A261815 a(n) = A261816(n)*A048617(n) for n > 1. %Y A261815 Cf. A006052, A048617, A261816. %K A261815 nonn,hard,more %O A261815 1,3 %A A261815 _Arkadiusz Wesolowski_, Nov 18 2015