

A170891


First differences of the toothpick sequence A170890.


4



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, 24, 22, 28, 40, 56, 52, 38, 28, 22, 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
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OFFSET

0,4


COMMENTS

Number of toothpicks added at nth stage to the toothpick structure of A170890.  Omar E. Pol, Jan 31 2013


LINKS

Table of n, a(n) for n=0..67.
David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n1)1) for n >= 2.]
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS


EXAMPLE

From Omar E. Pol, Jan 31 2013 (Start):
If written as an irregular triangle in which rows 0..4 have length 1, it appears that row j has length 2^(j5), if j >= 5.
0;
1;
1;
2;
3;
3;
4,7;
8,8,6,10;
8,10,12,20,20,16,12,14;
8,10,12,20,20,18,18,24,22,28,40,56,52,38,28,22;
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;
(End)


CROSSREFS

Cf. A139250, A139251, A170890, A170885, A170887, A170889, A170893.
Sequence in context: A035540 A114863 A152980 * A035535 A154309 A249579
Adjacent sequences: A170888 A170889 A170890 * A170892 A170893 A170894


KEYWORD

nonn,tabf


AUTHOR

Omar E. Pol, Jan 09 2010


EXTENSIONS

a(9) corrected by Omar E. Pol, following an observation by Kevin Ryde, Jan 29 2013
Terms beyond a(9) from M. F. Hasler, Jan 29 2013


STATUS

approved



