A173458 - OEIS

A173458

a(n) = A173457(n+1)/2.

4, 6, 2, 14, 18, 2, 14, 18, 6, 42, 54, 2, 14, 18, 6, 42, 54, 6, 42, 54, 18, 126, 162, 2, 14, 18, 6, 42, 54, 6, 42, 54, 18, 126, 162, 6, 42, 54, 18, 126, 162, 18, 126, 162, 54, 378, 486, 2, 14, 18, 6, 42, 54, 6, 42, 54, 18, 126, 162, 6, 42, 54, 18, 126, 162

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..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

EXAMPLE

From Omar E. Pol, Apr 22 2013 (Start):

When written as an irregular triangle begins:

4,6;

2,14,18;

2,14,18,6,42,54;

2,14,18,6,42,54,6,42,54,18,126,162;

2,14,18,6,42,54,6,42,54,18,126,162,6,42,54,18,126,162,18, 126,162,54,378,486;

2,14,18,6,42,54,6,42,54,18,126,162,6,42,54,18,126,162,...

(End)

CROSSREFS