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 A051566 #3 Sep 13 2003 03:00:00 %S A051566 0,5,0,2,138,47,1,12490 %N A051566 Erroneous version of A051567. %D A051566 M. Gardner, The Last Recreations, Springer, 1997, p. 282. %D A051566 M. Gardner, The Colossal Book of Mathematics, 2001, p. 209. %K A051566 dead %O A051566 3,2