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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 (list; graph; refs; listen; history; text; internal format)
 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.] N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS CROSSREFS Cf. A102376, A116520, A139250, A160120, A177241. Sequence in context: A146419 A162907 A165345 * A074741 A166701 A116520 Adjacent sequences:  A177237 A177238 A177239 * A177241 A177242 A177243 KEYWORD more,nonn AUTHOR Omar E. Pol, May 05 2010 EXTENSIONS Edited by Omar E. Pol, May 07 2010 STATUS approved

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Last modified January 28 07:07 EST 2020. Contains 331317 sequences. (Running on oeis4.)