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 A194440 #27 Mar 11 2014 01:34:18 %S A194440 0,1,3,7,11,15,19,27,35,39,43,51,63,79,87,103,119,123,127,135,147,163, %T A194440 179,203,229,253,265,285,313,353,373,405,437,441,445,453,465,481,497, %U A194440 521,547,571,591,623,663,727,767,815,869,909,921,941,973,1021 %N A194440 Number of toothpicks and D-toothpicks after n-th stage in the D-toothpick "wide" triangle of the second kind. %C A194440 For the D-toothpick "narrow" triangle of the second kind see A194442. %C A194440 The structure is essentially one of the wedges of several D-toothpick structures. For more information see A194270. The first differences (A194441) give the number of toothpicks or D-toothpicks added at n-th stage. [_Omar E. Pol_, Dec 29 2012] %H A194440 Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poltp062.jpg">Illustration of the structure after 32 stages</a> %H A194440 Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poltp063.jpg">Illustration of the structure after 64 stages</a> %H A194440 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 A194440 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %Y A194440 Cf. A139250, A160120, A160406, A161830, A194270, A194277, A194441, A194442, A194444, A194692, A194693, A194696, A220494, A220520. %K A194440 nonn %O A194440 0,3 %A A194440 _Omar E. Pol_, Aug 29 2011