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 A160421 #10 Feb 24 2021 02:48:18 %S A160421 5,8,14,14,16,28,38,26,16,28,40,44,60,92,98,50,16,28,40,44,60,92,100, %T A160421 68,60,96,124,148,212,280,242,98,16,28,40,44,60,92,100,68,60,96,124, %U A160421 148,212,280,244,116 %N A160421 First differences of A160420. %H A160421 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 A160421 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 A160421 Cf. A139250, A139251, A160420, A160422, A160423. %K A160421 nonn %O A160421 1,1 %A A160421 _Omar E. Pol_, Jun 01 2009 %E A160421 More terms from _Nathaniel Johnston_, Nov 13 2010