OFFSET
1,8
COMMENTS
It appears that the absolute value of a(n) is a multiple of 6, see A008588. - Omar E. Pol, Dec 06 2013
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.]
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
EXAMPLE
From Omar E. Pol, Dec 06 2013: (Start)
Written as an irregular triangle in which row lengths is A011782 the sequence begins:
0;
0;
0, 0;
0, 0, 0, 6;
0, 0, 0, 6, -6, 6, 0, 30;
0, 0, 0, 6, -6, 6, 0, 30, -12, 6, 0, 30...
(End)
CROSSREFS
KEYWORD
more,sign,tabf
AUTHOR
Omar E. Pol, May 29 2010
STATUS
approved