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 A139599 #9 Jan 30 2011 14:15:11 %S A139599 3,7,11,41,47,53,71,73,83,101,127,149,157,173,181,197,211,223,229,263, %T A139599 271,307,337,359,373,379,397,419,433,443,509,521,571,593,599,613,617, %U A139599 619,641,659,673,677,719,733,739,743,751,761,773,787,811,821,887,937 %N A139599 Duplicate of A141161. %K A139599 dead %O A139599 1,1