OFFSET
0,3
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 0..65535
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
FORMULA
G.f.: (x/((1-x)^2*(1+2*x))) * (1+2*x*prod(k>=0, 1+x^(2^k-1)+2*x^(2^k))). - Vincenzo Librandi, Aug 22 2014
MATHEMATICA
CoefficientList[Series[(x/((1 - x)^2 (1 + 2 x))) (1 + 2 x Product[1 + x^(2^k-1) + 2 x^(2^k), {k, 0, 20}]), {x, 0, 50}], x] (* Vincenzo Librandi, Aug 22 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, May 23 2009
EXTENSIONS
More terms from N. J. A. Sloane, May 17 2010
STATUS
approved