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 A194101 #5 Mar 30 2012 18:57:39 %S A194101 1,3,6,10,15,2,5,9,14,20,21,28,4,8,13,19,26,27,35,36,45,55,7,12,18,25, %T A194101 33,34,43,44,54,65,66,78,91,11,17,24,32,41,42,52,53,64,76,77,90,104, %U A194101 105,120,16,23,31,40,50,51,62,63,75,88,89,103,118,119,135,136,22 %N A194101 Inverse permutation of A194100; every positive integer occurs exactly once. %t A194101 (See A194100.) %Y A194101 Cf. A194100. %K A194101 nonn %O A194101 1,2 %A A194101 _Clark Kimberling_, Aug 15 2011