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 A233760 #8 Dec 19 2013 11:52:08 %S A233760 0,1,3,5,9,11,15,21,29,31,35,41,53,67,79,93,109,111,115,121,133,147, %T A233760 167,189,215,237,249,267,299,337,365,395,427,429,433,439,451,465,485, %U A233760 507,533,555,575,605,649,711,763,809,863,901,913,931,967,1013 %N A233760 Number of toothpicks and D-toothpicks after n-th stage in the D-toothpick "wide" triangle of the third kind, second version. %C A233760 The structure is essentially the same as A220520 but here the borders do not contain toothpicks with exposed endpoints except the initial toothpick. The structure is one of the oblique wedges of several D-toothpick structures. For more information see A220500. The first differences (A233761) give the number of toothpicks or D-toothpicks added at n-th stage. %H A233760 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 A233760 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %Y A233760 Cf. A139250, A220500, A220520, A233761, A233762, A233780. %K A233760 nonn %O A233760 0,3 %A A233760 _Omar E. Pol_, Dec 16 2013