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A161430 Fractal triangle whose virtual skeleton is a polyedge as the Y-toothpick structure of A160120. 5
0, 9, 33, 57, 123, 147 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Number of ON states after n generations of cellular automaton based on the infinite triangular grid.

LINKS

Table of n, a(n) for n=0..5.

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

CROSSREFS

Cf. A139250, A160120, A161341, A161342, A161343.

Sequence in context: A075812 A256868 A146262 * A175369 A046895 A165392

Adjacent sequences:  A161427 A161428 A161429 * A161431 A161432 A161433

KEYWORD

more,nonn

AUTHOR

Omar E. Pol, Jun 17 2009

STATUS

approved

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Last modified October 20 15:15 EDT 2019. Contains 328267 sequences. (Running on oeis4.)