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 A160430 #10 Feb 24 2021 02:48:18 %S A160430 0,5,13,29,57,85,113,145,209,329,509,613,665,697,761,881,1073,1273, %T A160430 1505,1817,2377,3217,4309,4761,4921,5009,5097,5233,5425,5625,5857, %U A160430 6169,6729,7569,8697,9425,10017,10641,11601,12873 %N A160430 The 3-D toothpick sequence A160160, but using toothpicks of length 4; a(n) is the number of nodes occupied after n steps. %H A160430 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 A160430 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> %F A160430 a(n) = A170884(n) + 2*A160160(n) %e A160430 Each toothpick looks like this: o-o-o-o-o. %e A160430 The initial (z-axis) toothpick occupies 5 nodes. The next two, in the x-direction, add 8 further nodes, and so on. %Y A160430 Cf. A139250, A139251, A147562, A160118, A160120, A160160, A160170, A160379, A160420. %K A160430 nonn %O A160430 0,2 %A A160430 _Omar E. Pol_, May 13 2009 %E A160430 Edited by _N. J. A. Sloane_, Jan 02 2010 %E A160430 Formula and more terms from _Nathaniel Johnston_, Nov 14 2010