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A160128 a(n) = number of grid points that are covered after (2^n)th stage of A139250. 5
3, 7, 19, 63, 235, 919, 3651, 14575, 58267, 233031, 932083, 3728287, 14913099, 59652343, 238609315, 954437199, 3817748731, 15270994855, 61083979347, 244335917311, 977343669163, 3909374676567, 15637498706179 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..22.

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

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

FORMULA

a(n) = A147614(A000079(n)).

a(n) = (1/9)*(2^(2*n+3) + 12*n + 19). [From Nathaniel Johnston, Mar 29 2011]

It appears that a(n) = A139252(2^(n+1)). - Omar E. Pol, Sep 11 2012

CROSSREFS

Cf. A000079, A007583, A139250, A139251, A139252, A139560, A147614.

Sequence in context: A148669 A249380 A210985 * A051139 A049423 A121825

Adjacent sequences:  A160125 A160126 A160127 * A160129 A160130 A160131

KEYWORD

nonn

AUTHOR

Omar E. Pol, May 09 2009

EXTENSIONS

Terms after a(10) from Nathaniel Johnston, Mar 29 2011

STATUS

approved

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Last modified February 25 04:05 EST 2018. Contains 299630 sequences. (Running on oeis4.)