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 A233972 #4 Dec 22 2013 00:00:13 %S A233972 1,1,2,1,2,3,4,1,2,3,5,5,4,7,8,1,2,3,5,5,5,9,12,11,4,7,11,13,8,15,16, %T A233972 1,2,3,5,5,5,9,12,11,5,9,14,19,14,23,28,27,4,7,11,13,11,21,28,31,8,15, %U A233972 23,29,16,31,32,1,2,3,5,5,5,9,12,11,5,9,14 %N A233972 a(n) = A233971(n+1)/2. %H A233972 N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a> %H A233972 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %e A233972 Written as an irregular triangle in which row lengths is A000079 the sequence begins: %e A233972 1, %e A233972 1,2, %e A233972 1,2,3,4, %e A233972 1,2,3,5,5,4,7,8, %e A233972 1,2,3,5,5,5,9,12,11,4,7,11,13,8,15,16, %e A233972 1,2,3,5,5,5,9,12,11,5,9,14,19,14,23,28,27,4,7,11,13,11,21, 28,31,8,15,23,29,16,31,32; %Y A233972 Right border gives A000079. %Y A233972 Cf. A139251, A233782, A233970, A233971. %K A233972 nonn,tabf %O A233972 1,3 %A A233972 _Omar E. Pol_, Dec 18 2013