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A161420 V-toothpick sequence starting from a V-toothpick whose central point touch a straight line, as a V. 3
0, 1, 3, 5, 7, 11, 19, 25, 31, 39, 51, 59, 69, 79, 99, 117, 127, 143, 163, 171 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
The sequence gives the number of V-toothpicks after n-th stages on hexagonal net. A161421 (the first differences) gives the number added at the n-th stage. See A161206 for more information.
Also, it appears this is a H-toothpick sequence in the first quadrant on the square grid, starting with a D-toothpick from the point (0,0). The sequence gives the number of toothpicks and D-toothpicks after n-th stage. A161421 (the first differences) gives the number added at the n-th stage. For more information see A182838.
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
Sequence in context: A144427 A082603 A362250 * A071997 A093442 A364920
KEYWORD
more,nonn
AUTHOR
Omar E. Pol, Jun 10 2009
STATUS
approved

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Last modified March 28 11:44 EDT 2024. Contains 371241 sequences. (Running on oeis4.)