A187213 Number of Q-toothpicks added at n-th stage to the structure of A187212.

0, 1, 2, 2, 4, 4, 8, 10, 8, 4, 8, 12, 12, 16, 28, 30, 16, 4, 8, 12, 12, 16, 28, 32, 20, 16, 28, 36, 40, 60, 88, 78, 32, 4, 8, 12, 12, 16, 28, 32, 20, 16, 28, 36, 40, 60, 88, 80, 36, 16, 28, 36, 40, 60, 88, 84, 56, 60, 92, 112

Offset

0,3

Comments

Essentially the first differences of A187212.

Links

Table of n, a(n) for n=0..59.

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.]

Nathaniel Johnston, The Q-Toothpick Cellular Automaton

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Formula

It appears that if n = 2^k - 1, for k >= 2, then a(n) = A139251(n) - 2 otherwise a(n) = A139251(n). - Omar E. Pol, Mar 30 2011

Example

Contribution from Omar E. Pol, Mar 29 2011 (Start):
If written as a triangle begins:
0,
1,
2,
2,4,
4,8,10,8,
4,8,12,12,16,28,30,16,
4,8,12,12,16,28,32,20,16,28,36,40,60,88,78,32,
(End)

Crossrefs

Cf. A139250, A139251, A187211, A187212, A187221.

Sequence in context: A318770 A284613 A000011 * A022476 A347206 A307240

Adjacent sequences: A187210 A187211 A187212 * A187214 A187215 A187216

Keyword

nonn

Author

Omar E. Pol, Mar 22 2011

Extensions

Terms after a(24) from Nathaniel Johnston, Mar 28 2011

Status

approved