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 A101438 #10 Apr 09 2014 10:12:20 %S A101438 1,2,3,5,7,4,9,11,6,13,15,8,17,19,21,10,23,25,12,27,29,31,14,33,35,16, %T A101438 37,39,41,18,43,45,20,47,49,22,51,53,55,24,57,59,26,61,63,65,28,67,69, %U A101438 30,71,73,32,75,77,79,34,81,83,36,85,87,89,38,91,93,40,95,97,42,99,101 %N A101438 Inverse permutation to A101369. %H A101438 Reinhard Zumkeller, <a href="/A101438/b101438.txt">Table of n, a(n) for n = 1..10000</a> %H A101438 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A101438 (Haskell) %o A101438 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A101438 a101438 = (+ 1) . fromJust . (`elemIndex` a101369_list) %o A101438 -- _Reinhard Zumkeller_, Jul 01 2013 %Y A101438 Cf. A101369. %K A101438 nonn %O A101438 1,2 %A A101438 _Leroy Quet_, Jan 18 2005 %E A101438 More terms from _David Wasserman_, Mar 27 2008