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 A179978 #2 Mar 30 2012 18:51:06 %S A179978 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,22,23,24,25,26,18,19,20,21, %T A179978 27,28,29,30,31,32,33,34,35,36,37,42,43,44,45,46,38,39,40,41,47,48,49, %U A179978 50,51,52,53,54,55,56,57,62,63,64,65,66,58,59,60,61,67,68,69,70,71,72 %N A179978 A108971(A108971(n)). %C A179978 a(A179979(n)) = A179979(n); %C A179978 A108971(n) = a(A179977(n)) = A179977(a(n)). %K A179978 nonn %O A179978 1,2 %A A179978 _Reinhard Zumkeller_, Aug 04 2010