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 A220512 #24 Sep 21 2024 08:41:05 %S A220512 0,4,12,28,44,60,88,136,168,184,216,280,344,424,508,620,684,700,732, %T A220512 796,892,1004,1148,1324,1460,1572,1668,1844,2020,2228,2424,2664,2792, %U A220512 2808,2840,2904,3000,3112,3264 %N A220512 D-toothpick sequence of the third kind starting with a cross formed by 4 toothpicks. %C A220512 This is a toothpick sequence of forking paths to 135 degrees. The sequence gives the number of toothpicks and D-toothpicks in the structure after n-th stage. A221565 (the first differences) give the number of toothpicks or D-toothpicks added at n-th stage. It appears that the structure has a fractal (or fractal-like) behavior. For more information see A194700. %C A220512 First differs from A194432 at a(14). %H A220512 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 A220512 turtle graphics, <a href="http://www.youtube.com/watch?v=A-oF8X_djMM">D-Toothpick Sequence</a>, Youtube video (2023) %H A220512 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %Y A220512 Cf. A139250, A194270, A194432, A194700, A220500, A220514, A220520, A220522, A220524, A220526. %K A220512 nonn,more %O A220512 0,2 %A A220512 _Omar E. Pol_, Dec 15 2012