cp's OEIS Frontend

A170891 First differences of the toothpick sequence A170890.

%I A170891 #33 Feb 24 2021 02:48:19
%S A170891 0,1,1,2,3,3,4,7,8,8,6,10,8,10,12,20,20,16,12,14,8,10,12,20,20,18,18,
%T A170891 24,22,28,40,56,52,38,28,22,8,10,12,20,20,18,18,24,22,28,40,56,52,40,
%U A170891 34,32,22,28,40,56,54,50,56,66,68,92,132,160,138,98,68,38
%N A170891 First differences of the toothpick sequence A170890.
%C A170891 Number of toothpicks added at n-th stage to the toothpick structure of A170890. - _Omar E. Pol_, Jan 31 2013
%H A170891 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 A170891 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>
%e A170891 From _Omar E. Pol_, Jan 31 2013 (Start):
%e A170891 If written as an irregular triangle in which rows 0..4 have length 1, it appears that row j has length 2^(j-5), if j >= 5.
%e A170891 0;
%e A170891 1;
%e A170891 1;
%e A170891 2;
%e A170891 3;
%e A170891 3;
%e A170891 4,7;
%e A170891 8,8,6,10;
%e A170891 8,10,12,20,20,16,12,14;
%e A170891 8,10,12,20,20,18,18,24,22,28,40,56,52,38,28,22;
%e A170891 8,10,12,20,20,18,18,24,22,28,40,56,52,40,34,32,22,28,40,56,54,50,56,66,68,92,132,160,138,98,68,38;
%e A170891 (End)
%Y A170891 Cf. A139250, A139251, A170890, A170885, A170887, A170889, A170893.
%K A170891 nonn,tabf
%O A170891 0,4
%A A170891 _Omar E. Pol_, Jan 09 2010
%E A170891 a(9) corrected by _Omar E. Pol_, following an observation by _Kevin Ryde_, Jan 29 2013
%E A170891 Terms beyond a(9) from _M. F. Hasler_, Jan 29 2013