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 A162793 #14 Feb 24 2021 02:48:18 %S A162793 1,4,4,12,4,12,16,32,4,12,16,32,16,36,60,80,4,12,16,32,16,36,60,80,16, %T A162793 36,60,84,60,112,208,192,4,12,16,32,16,36,60,80,16,36,60,84,60,112, %U A162793 208,192,16,36,60,84,60,112,208,196,60,112,208,224,212,364,672,448,4,12,16,32,16 %N A162793 Number of toothpicks added to the toothpick structure A139250 at the n-th odd round. %C A162793 Bisection of A139251. %C A162793 Note that these toothpicks are parallel to the initial toothpick in the structure. %C A162793 First differences of A162795. - _Omar E. Pol_, Feb 23 2015 %H A162793 David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.] %H A162793 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 A162793 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %e A162793 From _Omar E. Pol_, Feb 23 2015: (Start) %e A162793 Written as an irregular triangle in which the row lengths are the terms of A011782, the sequence begins: %e A162793 1; %e A162793 4; %e A162793 4,12; %e A162793 4,12,16,32; %e A162793 4,12,16,32,16,36,60,80; %e A162793 4,12,16,32,16,36,60,80,16,36,60,84,60,112,208,192; %e A162793 4,12,16,32,16,36,60,80,16,36,60,84,60,112,208,192,16,36,60,84,60,112,208,196,60,112,208,224,212,364,672,448; %e A162793 ... %e A162793 It appears that right border gives the positive terms of A001787. %e A162793 It appears that row sums give A000302. %e A162793 (End) %Y A162793 Cf. A000302, A001787, A139250, A139251, A147582, A159791, A159792, A162794, A162795, A162796, A162797, A169708. %K A162793 nonn,tabf %O A162793 1,2 %A A162793 _Omar E. Pol_, Jul 14 2009 %E A162793 More terms from _N. J. A. Sloane_, Dec 28 2009