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 A160408 #6 Feb 24 2021 02:48:18 %S A160408 0,1,2,4,8,12,16,20,24,32,48,64,72,76,80,88 %N A160408 Toothpick pyramid (see Comments lines for definition). %C A160408 The toothpick pyramid is a three-dimensional version of the toothpick triangle A160406. %C A160408 The sequence gives the number of toothpicks after n rounds. A160409 (the first differences) gives the number added at the n-th round. %C A160408 See also the entry A139250 for more information about the toothpick sequences. %H A160408 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 A160408 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 A160408 Cf. A139250, A139251, A160160, A160406, A160407, A160409. %K A160408 more,nonn %O A160408 0,3 %A A160408 _Omar E. Pol_, May 23 2009, Jun 06 2009