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 A194012 #5 Mar 30 2012 18:57:39 %S A194012 1,3,2,5,6,10,4,8,9,14,15,21,7,12,13,19,20,27,28,36,11,17,18,25,26,34, %T A194012 35,44,45,55,16,23,24,32,33,42,43,53,54,65,66,78,22,30,31,40,41,51,52, %U A194012 63,64,76,77,90,91,105,29,38,39,49,50,61,62,74,75,88,89,103 %N A194012 Inverse permutation of A194011; every positive integer occurs exactly once. %t A194012 (See A194011.) %Y A194012 Cf. A194011. %K A194012 nonn %O A194012 1,2 %A A194012 _Clark Kimberling_, Aug 15 2011