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 A241218 #4 Apr 17 2014 16:33:24 %S A241218 2,1,0,5,10,9,14,19,15,20,28,24,23,34,27,41,37,33,44,40,36,47,61,45, %T A241218 53,67,48,56,70,54,62,73,57,68,94,78,71,97,81,74,100,87,77,106,90,80, %U A241218 109,93,86,115,96,89,121,99,146,124,105,152,127,108,155,130 %N A241218 Smallest number m such that A240808(m) = n. %C A241218 A240808(a(n)) = n and A240808(m) <> n for m < a(n). %H A241218 Reinhard Zumkeller, <a href="/A241218/b241218.txt">Table of n, a(n) for n = 0..20000</a> %o A241218 (Haskell) %o A241218 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A241218 a241218 = fromJust . (`elemIndex` a240808_list) %Y A241218 Cf. A120511. %K A241218 nonn %O A241218 0,1 %A A241218 _Reinhard Zumkeller_, Apr 17 2014