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 A220526 #9 Mar 29 2013 12:27:32 %S A220526 0,1,3,7,11,15,19,26,34,38,42,50,62,76,88,103,119,123,127,135,147,163, %T A220526 183,207,233 %N A220526 Number of toothpicks and D-toothpicks after n-th stage in the structure of the D-toothpick "medium" triangle of the third kind. %C A220526 The structure is essentially one of the horizontal wedges of A220500. First differs from A194442 (and from A220522) at a(13). A220527 (the first differences) give the number of toothpicks or D-toothpicks added at n-th stage. %H A220526 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 A220526 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %Y A220526 Cf. A139250, A194270, A194440, A194700, A194442, A220500, A220512, A220514, A220520, A220522, A220524, A220527. %K A220526 nonn,more %O A220526 0,3 %A A220526 _Omar E. Pol_, Jan 02 2013