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 A095767 #8 Mar 29 2015 19:31:45
%S A095767 0,0,1,1,0,2,2,2,0,1,0,0,3,3,3,3,0,1,0,2,2,0,1,1,0,0,0,4,4,4,4,4,0,1,
%T A095767 0,2,0,0,1,0,3,3,0,1,1,0,0,0,2,0,0,1,1,1,0,0,0,0,5,5,5,5,5,5,0,1,0,2,
%U A095767 0,1,1,0,3,0,1,1,0,2,0,0,1,0,0,4,4,4,0,1,0,0,2,0,0,1,1,1,0,3,3,0,0,0,1,1,1
%N A095767 a(n) = valuation(A004001(n),2).
%F A095767 Partial formula: a(2^(n+1) - n + i) = n for 0<=i<=n.
%t A095767 a[1] = a[2] = 1; a[n_] := a[n] = a[a[n - 1]] + a[n - a[n - 1]]; f[n_] := Length[ NestWhileList[ #/2 &, n, IntegerQ[ # ] &]] - 2; Table[ f[ a[n]], {n, 105}] (* _Robert G. Wilson v_, Jun 11 2004 *)
%Y A095767 Cf. A095768.
%K A095767 nonn
%O A095767 1,6
%A A095767 _Benoit Cloitre_, Jun 05 2004