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 A124592 #4 Mar 30 2012 16:50:36 %S A124592 2,4,63,196,15125,838566,807905287,19896463928,3059220303009, %T A124592 3931520917431250 %N A124592 Ends of the runs of numbers described in A072875. %F A124592 a(n) = A072875(n)+n-1. %K A124592 nonn %O A124592 1,1 %A A124592 _N. J. A. Sloane_, Jan 28 2007