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A177240
Number of K-toothpicks after n stages of 3-D K-toothpick structure defined in Comments.
1
0, 1, 5, 9, 25, 29, 45
OFFSET
0,3
COMMENTS
We are in 3-D. Here the polytoothpick is a K-toothpick. The K-toothpick has 4 components or line segments, a central point and 4 endpoints, as a tetrapod but without volume. The K-toothpick endpoints coincide with the vertices of a regular tetrahedron.
It appears that this is a three-dimensional version of A160120, but with K-toothpicks, not with Y-toothpick.
The first differences are in the entry A177241.
For the toothpick mechanism see A139250 and A160120.
Question: Is this the same as A116520? (To answer the question we need a program because the structure is hard to visualize).
LINKS
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.]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Omar E. Pol, May 05 2010
EXTENSIONS
Edited by Omar E. Pol, May 07 2010
STATUS
approved