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A160407 First differences of toothpick numbers A160406. 20
1, 1, 2, 2, 2, 2, 4, 4, 2, 2, 4, 4, 4, 6, 10, 8, 2, 2, 4, 4, 4, 6, 10, 8, 4, 6, 10, 10, 12, 20, 26, 16, 2, 2, 4, 4, 4, 6, 10, 8, 4, 6, 10, 10, 12, 20, 26, 16, 4, 6, 10, 10, 12, 20, 26, 18, 12, 20, 28, 30, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Number of toothpicks added at n-th stage in the toothpick structure of A160406.

LINKS

Table of n, a(n) for n=1..61.

David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, 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.]

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

EXAMPLE

Contribution from Omar E. Pol, Jul 18 2009: (Start)

If written as a triangle:

1;

1;

2,2;

2,2,4,4;

2,2,4,4,4,6,10,8;

2,2,4,4,4,6,10,8,4,6,10,10,12,20,26,16;

2,2,4,4,4,6,10,8,4,6,10,10,12,20,26,16,4,6,10,10,12,20,26,18,12,20,28,30,42;...

(End)

CROSSREFS

Cf. A139250, A139251, A153000, A153006, A152980, A160406, A161830, A161831.

Sequence in context: A051464 A151565 A060632 * A007457 A119802 A237120

Adjacent sequences:  A160404 A160405 A160406 * A160408 A160409 A160410

KEYWORD

nonn

AUTHOR

Omar E. Pol, May 23 2009

EXTENSIONS

More terms from N. J. A. Sloane, Jul 17 2009

STATUS

approved

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Last modified January 18 11:33 EST 2019. Contains 319271 sequences. (Running on oeis4.)