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 A162777 #11 Feb 24 2021 02:48:18 %S A162777 0,0,1,1,1,3,5,3,1,3,5,5,7,13,15,7,1,3,5,5,7,13,15,9,7,13,17,19,29,43, %T A162777 39,15,1,3,5,5,7,13,15,9,7,13,17,19,29,43,39,17,7,13,17,19,29,43,41, %U A162777 27,29,45,55,69,103,127,95,31 %N A162777 a(n) = A153003(n) - A153006(n). %C A162777 The main entry for this sequence is the toothpick sequence A139250. %H A162777 Jinyuan Wang, <a href="/A162777/b162777.txt">Rows n = 0..14 of triangle, flattened</a> %H A162777 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 A162777 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 A162777 Observation: It appears that a(2^i) = 1, i > 0 and a(2^i-1) = 2^(i-1) - 1, i > 0. %e A162777 If written as a triangle: %e A162777 0; %e A162777 0; %e A162777 1,1; %e A162777 1,3,5,3; %e A162777 1,3,5,5,7,13,15,7; %e A162777 1,3,5,5,7,13,15,9,7,13,17,19,29,43,39,15; %e A162777 ... %e A162777 Rows converge to A162779. %Y A162777 Cf. A139250, A152980, A153003, A153004, A153006, A162779. %K A162777 nonn,tabf %O A162777 0,6 %A A162777 _Omar E. Pol_, Jul 23 2009 %E A162777 More terms from _Jinyuan Wang_, Mar 15 2020