

A161426


Ytoothpick sequence starting at the outside corner of an infinite triangleshaped polygon as the sieve of A160120 after 2^k rounds.


2



0, 1, 4, 7, 14, 19, 26, 35, 52, 63, 70
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OFFSET

0,3


COMMENTS

The sequence gives the number of Ytoothpicks after n rounds. A161427 (the first differences) gives the number added at the nth round.
See the entries A160120, A139250 and A153006 for more information.


LINKS

Table of n, a(n) for n=0..10.
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
David Applegate, The movie version


CROSSREFS

Cf. A000079, A139250, A153006, A160120, A161427, A161830.
Sequence in context: A049766 A244905 A310920 * A115759 A157615 A188319
Adjacent sequences: A161423 A161424 A161425 * A161427 A161428 A161429


KEYWORD

more,nonn


AUTHOR

Omar E. Pol and David Applegate, Jun 20 2009


STATUS

approved



