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A172309
Number of L-toothpicks added to the L-toothpick structure of A172308 (First quadrant) at the n-th stage.
6
0, 1, 2, 2, 2, 4, 4, 2, 4, 6, 6, 8, 6, 12, 10, 6, 4, 6, 10, 12, 10, 14, 14, 16, 16, 18, 14, 16, 12, 20, 22, 8, 8, 16, 18, 16, 10, 16, 20, 24, 26, 36, 24, 32, 30, 40, 28, 24
OFFSET
0,3
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.]
FORMULA
a(0) = 0, a(n) = A172305(n+1)/4, for n>=1.
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Omar E. Pol, Feb 06 2010
EXTENSIONS
More terms from Colin Barker, Apr 19 2015
STATUS
approved