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A170891 First differences of the toothpick sequence A170890. 4

%I #33 Feb 24 2021 02:48:19

%S 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 24,22,28,40,56,52,38,28,22,8,10,12,20,20,18,18,24,22,28,40,56,52,40,

%U 34,32,22,28,40,56,54,50,56,66,68,92,132,160,138,98,68,38

%N First differences of the toothpick sequence A170890.

%C Number of toothpicks added at n-th stage to the toothpick structure of A170890. - _Omar E. Pol_, Jan 31 2013

%H 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 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 From _Omar E. Pol_, Jan 31 2013 (Start):

%e 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 0;

%e 1;

%e 1;

%e 2;

%e 3;

%e 3;

%e 4,7;

%e 8,8,6,10;

%e 8,10,12,20,20,16,12,14;

%e 8,10,12,20,20,18,18,24,22,28,40,56,52,38,28,22;

%e 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 (End)

%Y Cf. A139250, A139251, A170890, A170885, A170887, A170889, A170893.

%K nonn,tabf

%O 0,4

%A _Omar E. Pol_, Jan 09 2010

%E a(9) corrected by _Omar E. Pol_, following an observation by _Kevin Ryde_, Jan 29 2013

%E Terms beyond a(9) from _M. F. Hasler_, Jan 29 2013

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Last modified April 25 01:06 EDT 2024. Contains 371964 sequences. (Running on oeis4.)