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A161421
First differences of A161420.
3
0, 1, 2, 2, 2, 4, 8, 6, 6, 8, 12, 8, 10, 10, 20, 18, 10, 16, 20, 8
OFFSET
0,3
COMMENTS
Number of V-toothpicks added at the n-th stage to the V-toothpick structure of A161420. See also A161206 and A161207.
Also it appears a(n) is also the number of toothpicks and D-toothpicks added at n-th stage to the H-toothpick structure of A161420. See also A182838 and A182839.
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.]
KEYWORD
more,nonn
AUTHOR
Omar E. Pol, Jun 10 2009, Dec 12 2010
STATUS
approved