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 A326664 #15 Feb 06 2023 10:01:43
%S A326664 7,16,25,35,43,52,61,71,79,88,97,107,115,124,133,142,151,160,169,179,
%T A326664 187,196,205,215,223,232,241,251,259,268,277,286,295,304,313,323,331,
%U A326664 340,349,359,367,376,385,395,403,412,421,430,439,448,457,467,475,484
%N A326664 Column 3 of the array at A326661 see Comments.
%C A326664 This is the sequence (c(n)) defined by the complementary equation c(n) = a(n) + b(3n), with initial value a(1) = 1. See A326661. Conjecture: 9n-c(n) is in {1,2} for all n.
%H A326664 Clark Kimberling, <a href="/A326664/b326664.txt">Table of n, a(n) for n = 1..10000</a>
%t A326664 mex[list_, start_] := (NestWhile[# + 1 &, start, MemberQ[list, #] &]);
%t A326664 a = b = c = {}; h = 1; k = 3;
%t A326664 Do[Do[AppendTo[a,
%t A326664 mex[Flatten[{a, b, c}], Max[Last[a /. {} -> {0}], 1]]];
%t A326664 AppendTo[b, mex[Flatten[{a, b, c}], Max[Last[b /. {} -> {0}], 1]]], {k}];
%t A326664 AppendTo[c, a[[h Length[a]/k]] + Last[b]], {150}]; c
%t A326664 (* _Peter J. C. Moses_, Jul 04 2019 *)
%Y A326664 Cf. A326661.
%K A326664 nonn,easy
%O A326664 1,1
%A A326664 _Clark Kimberling_, Jul 16 2019