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 A120514 #23 Jan 10 2022 12:23:16
%S A120514 1,2,3,5,6,7,9,10,11,14,15,16,18,19,20,22,23,24,27,28,29,31,32,33,35,
%T A120514 36,37,41,42,43,45,46,47,49,50,51,54,55,56,58,59,60,62,63,64,67,68,69,
%U A120514 71,72,73,75,76,77,81,82,83,85,86,87,89,90,91,94,95,96,98
%N A120514 a(n) = min{j : A120503(j) = n}.
%H A120514 Benoit Cloitre, <a href="/A120514/a120514.png">3^13 steps of the walk using step: turn 90° right if a(n)is even and turn 90° left if a(n) is odd</a>
%H A120514 C. Deugau and F. Ruskey, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL12/Ruskey/ruskey6.html">Complete k-ary Trees and Generalized Meta-Fibonacci Sequences</a>, J. Integer Seq., Vol. 12. [This is a later version than that in the GenMetaFib.html link]
%H A120514 C. Deugau and F. Ruskey, <a href="http://www.cs.uvic.ca/~ruskey/Publications/MetaFib/GenMetaFib.html">Complete k-ary Trees and Generalized Meta-Fibonacci Sequences</a>
%F A120514 G.f.: P(z) = z / (1-z) * (1 + Sum_{m>=0} z^(m^3)/(1 - z^(m^3))).
%F A120514 a(1) = 1; a(n) = n-1 + a(floor((n-1)/3)+1). - _Gleb Ivanov_, Jan 10 2022
%p A120514 p := proc(n)
%p A120514 if n=1 then return 1; end if;
%p A120514 for j from p(n-1)+1 to infinity do
%p A120514 if A120503(j) = n then return j; fi; od;
%p A120514 end proc;
%Y A120514 Cf. A120503, A120525, A005187.
%K A120514 nonn
%O A120514 1,2
%A A120514 _Frank Ruskey_ and Chris Deugau (deugaucj(AT)uvic.ca), Jun 20 2006