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 A139826 #2 Mar 30 2012 17:22:48 %S A139826 1,2,3,5,6,7,10,13,15,21,22,30,33,37,42,57,58,70,78,85,93,102,105,130, %T A139826 133,165,177,190,210,253,273,330,345,357,385,462,1365 %N A139826 Squarefree idoneal numbers (A000926). %K A139826 fini,full,nonn %O A139826 1,2 %A A139826 _T. D. Noe_, May 06 2008