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 A022955 #9 Apr 05 2016 10:25:58
%S A022955 1,2,3,5,8,10,14,19,22,27,34,38,44,52,58,65,75,82,90,101,110,119,131,
%T A022955 141,151,164,176,187,201,215,227,242,257,270,287,303,317,335,352,367,
%U A022955 386,405,421,441,461,478,500,521,539,562,584,603,628,651
%N A022955 Unique increasing sequence satisfying a(n) = a(n-3) + c(n-3); where c( ) is complement of a( ).
%C A022955 Here "complement" refers to the numbers not in the sequence.
%H A022955 Ivan Neretin, <a href="/A022955/b022955.txt">Table of n, a(n) for n = 1..10000</a>
%t A022955 Fold[Append[#1, #1[[#2]] + Complement[Range[Max@#1 + 1], #1][[#2]]] &, {1, 2, 3}, Range[50]] (* _Ivan Neretin_, Apr 05 2016 *)
%Y A022955 Cf. A005228 and references therein.
%K A022955 nonn
%O A022955 1,2
%A A022955 _Clark Kimberling_