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 A160419 #6 Feb 24 2021 02:48:18 %S A160419 1,2,2,2,2,2,4,8 %N A160419 a(n) = A160409(n+2)/2. %H A160419 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 A160419 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 A160419 Cf. A139250, A139251, A160160, A160161, A160406, A160407, A160408, A160409, A160418. %K A160419 more,nonn %O A160419 1,2 %A A160419 _Omar E. Pol_, May 23 2009