A170852 G.f.: Product_{k>=2} (1 + 3x^(2^k-1) + 3x^(2^k)).

1, 0, 0, 3, 3, 0, 0, 3, 3, 0, 9, 18, 9, 0, 0, 3, 3, 0, 9, 18, 9, 0, 9, 18, 9, 27, 81, 81, 27, 0, 0, 3, 3, 0, 9, 18, 9, 0, 9, 18, 9, 27, 81, 81, 27, 0, 9, 18, 9, 27, 81, 81, 27, 27, 81, 81, 108, 324, 486, 324, 81, 0, 0, 3, 3, 0, 9, 18, 9, 0, 9, 18, 9, 27, 81, 81, 27, 0, 9, 18, 9, 27, 81, 81, 27

Offset: 0

Author

N. J. A. Sloane, Jan 02 2010

Keywords

• nonn

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