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 A061571 #3 May 11 2007 03:00:00 %S A061571 0,1,3,5,9,13,17,23,31,37,45,55,63,75,87,95,111,127,139,157,173,185, %T A061571 205 %N A061571 Duplicate of A049690. %K A061571 dead %O A061571 0,3