OFFSET
0,2
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
FORMULA
Sum_{i=0 .. 2^k - 1} a(i) = 4^i - 2^i - 2 for k >= 2 (cf. A170940).
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 04 2010
STATUS
approved