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 A087931 #5 Mar 31 2012 12:35:01 %S A087931 512,3020819005440,2980039854936078219167744 %N A087931 Number of ways of arranging the numbers 1 ... 10n into a 10 X n array so there is exactly one local maximum. %Y A087931 A row of the array in A087783. Cf. A007846. %K A087931 nonn,bref %O A087931 1,1 %A A087931 _R. H. Hardin_, Oct 27 2003