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 A022437 #6 Mar 30 2017 04:49:50
%S A022437 2,3,4,7,13,15,18,20,22,25,28,31,35,38,42,45,49,51,55,57,61,63,66,69,
%T A022437 71,75,77,80,83,85,89,91,94,97,100,103,106,109,112,115,118,121,124,
%U A022437 127,131,133
%N A022437 a(n) = c(n-1) + c(n-3) where c is the sequence of numbers not in a.
%H A022437 Ivan Neretin, <a href="/A022437/b022437.txt">Table of n, a(n) for n = 0..10000</a>
%t A022437 Fold[Append[#1, Plus @@ Complement[Range[Max@#1 + 3], #1][[{#2, #2 + 2}]]] &, {2, 3, 4}, Range[43]] (* _Ivan Neretin_, Mar 30 2017 *)
%Y A022437 Cf. A022424 and references therein.
%K A022437 nonn
%O A022437 0,1
%A A022437 _Clark Kimberling_