



0, 1, 2, 4, 4, 4, 8, 16, 8, 4, 8, 16, 16, 16, 32, 64, 16, 4, 8, 16, 16, 16, 32, 64, 32, 16, 32, 64, 64, 64, 128, 256, 32, 4, 8, 16, 16, 16, 32, 64, 32, 16, 32, 64, 64, 64, 128, 256, 64, 16, 32, 64, 64, 64, 128, 256, 128, 64, 128, 256, 256
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OFFSET

0,3


COMMENTS

First differences of A173530.
Number of triangles (Or Vtoothpicks, or Ltoothpicks, etc.) added in the threedimensional structure of A173530 at the nth stage.


LINKS

Table of n, a(n) for n=0..60.
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

If written as a triangle, begins:
0;
1;
2;
4,4;
4,8,16,8;
4,8,16,16,16,32,64,16;
4,8,16,16,16,32,64,32,16,32,64,64,64,128,256,32;
4,8,16,16,16,32,64,32,16,32,64,64,64,128,256,64,16,32,64,64,64,128,256,128,...


CROSSREFS

Cf. A001316, A047999, A060632, A139250, A139251, A161207, A172311, A173530, A173532.
Sequence in context: A139251 A182635 A188346 * A122788 A078003 A081524
Adjacent sequences: A173528 A173529 A173530 * A173532 A173533 A173534


KEYWORD

nonn


AUTHOR

Omar E. Pol, Oct 10 2010


STATUS

approved



