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 A213338 #6 Jun 09 2012 04:54:09 %S A213338 1,1,2,2,10,26,32,74,54,198,486,726,1112,1438,1570,1576,1220,954,888, %T A213338 464,194,116,48,8,0,0,0,36,0 %N A213338 Costas arrays such that the corresponding permutation is cyclic. %H A213338 Scott Rickard, <a href="http://costasarrays.org/">costasarrays.org</a> (information and papers about Costas arrays). %Y A213338 Cf. A008404 (Costas arrays), A213270 (Costas arrays that are involutions), A213271 (Costas arrays that are derangements), A213339 (Costas arrays that are connected). %K A213338 nonn,hard,more %O A213338 1,3 %A A213338 _Joerg Arndt_, Jun 09 2012