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 A325523 #7 May 06 2019 21:22:59
%S A325523 3,1,5,1,2,1,5,3,1,2,1,2,3,1,5,3,1,3,2,3,1,2,1,2,3,1,5,1,2,1,3,2,3,1,
%T A325523 5,3,1,5,1,2,1,5,3,1,2,3,3,1,5,1,2,1,3,2,3,1,2,1,2,3,1,5,1,2,1,3,2,3,
%U A325523 1,3,2,3,1,5,1,2,1,5,3,1,2,3,3,1,5,3
%N A325523 Difference sequence of A325430.
%C A325523 See A325417 for a guide to related sequences. Conjecture: every term is in {1,2,3,5}.
%H A325523 Clark Kimberling, <a href="/A325523/b325523.txt">Table of n, a(n) for n = 1..10000</a>
%t A325523 a = {1}; Do[AppendTo[a, NestWhile[# + 1 &, Last[a] + 1, Apply[Or,
%t A325523 Map[MemberQ[a, #] &, Select[Flatten[{#/3,
%t A325523 If[Mod[#, 3] == 0, (2 #)/3, 0] + If[Mod[#, 3] == 1, 1/3 (1 + 2 #), 0]}],
%t A325523 IntegerQ || # == 0]]] &]], {20000}]; a ; (* A325429 *)
%t A325523 c = Complement[Range[Last[a]], a] ; (* A325430 *)
%t A325523 Differences[a] (* A325522 *)
%t A325523 Differences[c] (* A325523 *)
%t A325523 (* _Peter J. C. Moses_, Apr 23 2019 *)
%Y A325523 Cf. A325417, A325430, A325522.
%K A325523 nonn,easy
%O A325523 1,1
%A A325523 _Clark Kimberling_, May 06 2019