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 A218454 #21 Jul 13 2013 12:04:32 %S A218454 1,2,4,6,8,3,18,20,11,13,40,5,64,24,12,30,395,82,120,7,22,69,172,45, %T A218454 14,224,36,21,23163,9,501,124,38,325,93,48,424,389,73,107,10424,17, %U A218454 588,125,10,591,39202,143,23,33,150,71,18422,46,94,19,203,931,1085 %N A218454 Smallest number m such that A176352(m) = n. %C A218454 A176352(a(n)) = n; if A176352 is a permutation of the natural numbers, then this sequence is its inverse. %H A218454 Reinhard Zumkeller, <a href="/A218454/b218454.txt">Table of n, a(n) for n = 1..250</a> %o A218454 (Haskell) %o A218454 import Data.List (elemIndex) %o A218454 import Data.Maybe (fromJust) %o A218454 a218454 = (+ 1) . fromJust . (`elemIndex` a176352_list) %K A218454 nonn %O A218454 1,2 %A A218454 _Reinhard Zumkeller_, Oct 30 2012