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 A120238 #2 Mar 30 2012 18:57:06 %S A120238 1,2,5,3,4,9,10,6,7,15,8,17,19,20,11,12,25,13,14,29,30,16,33,34,18,37, %T A120238 39,40,21,43,22,23,24,49,50,26,53,27,28,57,58,60,31,63,32,66,67,68,35, %U A120238 36,73,74,38,77,78,80,41,83,42,85,87,44,45,91,46,47,48,97,98,99,101,51 %N A120238 Inverse of A120237. %C A120238 A permutation of the natural numbers. %Y A120238 Cf. A120229, A120237. %K A120238 nonn %O A120238 1,2 %A A120238 _Clark Kimberling_, Jun 11 2006