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 A151549 #6 Dec 03 2013 13:24:51 %S A151549 0,1,2,3,2,5,8,7,2,5,8,9,10,19,24,15,2,5,8,9,10,19,24,17,10,19,26,29, %T A151549 40,63,64,31,2,5,8,9,10,19,24,17,10,19,26,29,40,63,64,33,10,19,26,29, %U A151549 40,63,66,45,40,65,82,99,144,191,160,63,2,5,8,9,10,19,24,17,10,19,26,29,40,63 %N A151549 a(n) = (A151548(n)-1)/2. %H A151549 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> %e A151549 From _Omar E. Pol_, Nov 30 2013: (Start) %e A151549 Written as an irregular triangle in which row lengths is A011782 the right border gives A000225. %e A151549 Triangle begins: %e A151549 0; %e A151549 1; %e A151549 2,3; %e A151549 2,5,8,7; %e A151549 2,5,8,9,10,19,24,15; %e A151549 2,5,8,9,10,19,24,17,10,19,26,29,40,63,64,31; %e A151549 2,5,8,9,10,19,24,17,10,19,26,29,40,63,64,33,10,19,26,29,40,63,66,45,40,65,82,99,144,191,160,63; %e A151549 (End) %Y A151549 Cf. A160552. %K A151549 nonn,tabf %O A151549 0,3 %A A151549 _N. J. A. Sloane_, May 18 2009