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 A147952 #17 Dec 28 2023 19:30:45
%S A147952 0,1,1,2,2,3,2,3,4,3,3,5,3,4,5,4,5,7,4,4,6,4,4,8,4,6,6,4,4,8,4,6,10,5,
%T A147952 6,7,4,5,9,5,5,8,6,7,7,5,5,10,6,6,7,5,6,8,4,6,8,4,6,8,4,6,10,4,5,8,5,
%U A147952 6,8,6,8,6,6,4,10,4,5,8,5,6,13,4,6,8,4,6,8,6,8,6,6,4,10,4,5,8,6,7,10,6,6
%N A147952 a(0) = 0, a(1) = a(2) = 1, and for n >= 3, a(n) = a(a(n-2)) + r(n), where r(n) = a(a(floor(n/3))) when n == 0 or 1 (mod 3) and = a(n - a(floor(n/3))) when n == 2 (mod 3).
%F A147952 a(n) = a(a(n - 2)) + If[Mod[n, 3] == 0, a(a(n/3)), If[Mod[n, 3] == 1, a(a((n - 1)/3)), a(n - a((n - 2)/3))] for n >= 3 with a(0) = 0 and a(1) = a(2) = 1. [edited by _Petros Hadjicostas_, Apr 13 2020]
%t A147952 f[0] = 0; f[1] = 1; f[2] = 1; f[n_] := f[n] = f[f[n - 2]] + If[Mod[n, 3] == 0,f[f[n/3]], If[Mod[n, 3] == 1, f[f[(n - 1)/3]], f[n - f[(n - 2)/3]]]]; Table[f[n], {n, 0, 100}]
%Y A147952 Cf. A147665, A147953, A147981.
%K A147952 nonn
%O A147952 0,4
%A A147952 _Roger L. Bagula_, Nov 17 2008
%E A147952 Name edited by _Petros Hadjicostas_, Apr 13 2020