A170872 a(0) = 1, a(1) = 2; a(2^i + j) = 3a(j) + 3a(j + 1) for 0 <= j < 2^i.

1, 2, 9, 33, 9, 33, 126, 126, 9, 33, 126, 126, 126, 477, 756, 405, 9, 33, 126, 126, 126, 477, 756, 405, 126, 477, 756, 756, 1809, 3699, 3483, 1242, 9, 33, 126, 126, 126, 477, 756, 405, 126, 477, 756, 756, 1809, 3699, 3483, 1242, 126, 477, 756, 756, 1809, 3699, 3483, 1593

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