OFFSET
1,2
COMMENTS
Number of toothpicks added to the spiral at the n-th stage.
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..254
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
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, May 26 2009
EXTENSIONS
Terms after a(12) from Nathaniel Johnston, Mar 30 2011
STATUS
approved