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 A170878 #6 Feb 24 2021 02:48:19 %S A170878 4,0,12,-12,20,-8,44,-56,20,0,60,-68,68,-24,156,-212,20,0,60,-60,100, %T A170878 -40,220,-288,68,0,204,-228,244,-88,556,-768,20,0,60,-60,100,-40,220, %U A170878 -280,100,0,300,-340,340,-120,780,-1068,68,0,204,-204,340,-136,748,-976,244,0,732,-820,868,-312,1980,-2748 %N A170878 First differences of A072272. %H A170878 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 A170878 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> %K A170878 sign %O A170878 0,1 %A A170878 _N. J. A. Sloane_, Jan 07 2010, Apr 17 2010