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 A139603 #7 Nov 27 2010 14:20:36 %S A139603 2,7,11,19,43,79,83,107,127,131,139,151,167,211,227,239,263,271,283, %T A139603 307,347,359,431,439,479,491,503,523,547,563,571,607,659,739,743,787, %U A139603 811,827,887,919,967 %N A139603 Duplicate of A141183. %K A139603 dead %O A139603 1,1