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 A194081 #20 Nov 21 2013 13:12:29
%S A194081 0,1,3,4,5,6,8,10,11,13,14,15,17,18,19,20,22,23,24,25,27,29,30,31,32,
%T A194081 34,36,37,39,40,41,42,44,46,47,49,50,51,53,54,55,56,58,60,61,63,64,65,
%U A194081 67,68,69,70,72,73,74,75,77,79,80,82,83,84,86,87,88,89
%N A194081 Smallest m such that A005375(m) = n.
%C A194081 A005375(a(n)) = n and A005375(m) <> n for m < a(n).
%H A194081 Reinhard Zumkeller, <a href="/A194081/b194081.txt">Table of n, a(n) for n = 0..10000</a>
%H A194081 <a href="/index/Ho#Hofstadter">Index entries for Hofstadter-type sequences</a>
%H A194081 <a href="/index/Go#GEB">Index entries for sequences from "Goedel, Escher, Bach"</a>
%t A194081 a[0] := 0; a[n_] := a[n] = a[n] = n - a[a[a[a[n - 1]]]]; Table[Select[Range[0, 199], a[#] == n &][[1]], {n, 0, 65}] (* _Alonso del Arte_, Aug 17 2011 *)
%o A194081 (Haskell)
%o A194081 import Data.List (elemIndex)
%o A194081 import Data.Maybe (fromJust)
%o A194081 a194081 n = a194081_list !! n
%o A194081 a194081_list = map (fromJust . (`elemIndex` a005375_list)) [0..]
%K A194081 nonn
%O A194081 0,3
%A A194081 _Reinhard Zumkeller_, Aug 17 2011