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 A172307 #15 Feb 05 2025 16:18:35 %S A172307 0,1,2,4,4,4,8,8,4,8,12,12,16,12,24,20,12,8,12,20,24,20,28,28,32,32, %T A172307 36,28,32,24,40,44,16,16,32,36,32,20,32,40,48,52,72,48,64,60,80,56,48, %U A172307 40,64,64,72,44,68,64,68,72,84,84,108,80,96,84,32,40,64 %N A172307 a(n) = A172305(n)/2. %H A172307 Robert Price, <a href="/A172307/b172307.txt">Table of n, a(n) for n = 0..202</a> %H A172307 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 A172307 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> %Y A172307 Cf. A139250, A172304, A172305, A172306, A172308, A172309, A172310, A172311, A172312, A172313. %K A172307 nonn %O A172307 0,3 %A A172307 _Omar E. Pol_, Feb 06 2010 %E A172307 a(14)-a(66) from _Robert Price_, Jun 17 2019