A183061 - OEIS

A183061

First differences of A183060.

0, 1, 3, 3, 7, 3, 7, 7, 19, 3, 7, 7, 19, 7, 19, 19, 55, 3, 7, 7, 19, 7, 19, 19, 55, 7, 19, 19, 55, 19, 55, 55, 163, 3, 7, 7, 19, 7, 19, 19, 55, 7, 19, 19, 55, 19, 55, 55, 163, 7, 19, 19, 55, 19, 55, 55, 163, 19, 55, 55, 163, 55, 163, 163, 487, 3

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OFFSET

0,3

COMMENTS

The sequence gives the number of cells turned "ON" at the n-th stage in the structure of A183060.

LINKS

Table of n, a(n) for n=0..65.

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

Index entries for sequences related to cellular automata

FORMULA

a(n) = 1 + A147582(n)/2.

a(n) = 1 + 2*A147610(n).

EXAMPLE

If written as a triangle begins:

3,7,

3,7,7,19,

3,7,7,19,7,19,19,55,

3,7,7,19,7,19,19,55,7,19,19,55,19,55,55,163,

It appears that row sums give A007582.