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 A194985 #5 Mar 30 2012 18:57:44 %S A194985 1,3,2,5,6,4,8,10,9,7,12,14,15,13,11,17,19,21,20,18,16,23,25,27,28,26, %T A194985 24,22,30,32,34,36,35,33,31,29,38,40,42,44,45,43,41,39,37,47,49,51,53, %U A194985 55,54,52,50,48,46,57,59,61,63,66,65,64,62,60,58,56,68,70,72 %N A194985 Inverse permutation of A194984; every positive integer occurs exactly once. %t A194985 (See A194984.) %Y A194985 Cf. A194984, A194954. %K A194985 nonn %O A194985 1,2 %A A194985 _Clark Kimberling_, Sep 07 2011