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 A160427 #10 Feb 24 2021 02:48:18 %S A160427 5,4,8,13,12,10,17,21,12,10,17,21,20,26,41,37,12,10,17,21,20,26,41,37, %T A160427 20,26,41,45,52,82,105,69,12,10,17,21,20,26,41,37,20,26,41,45,52,82, %U A160427 105,69,20,26,41,45,52,82,105 %N A160427 First differences of A160426. %H A160427 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 A160427 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 A160427 Cf. A139250, A139251. %K A160427 nonn %O A160427 1,1 %A A160427 _Omar E. Pol_, May 25 2009 %E A160427 Terms after a(13) from _Nathaniel Johnston_, Mar 31 2011