A170861 a(0) = 1, a(1) = 0; a(2^i + j) = 2a(j) + 3a(j + 1) for 0 <= j < 2^i.

1, 0, 2, 6, 2, 6, 22, 18, 2, 6, 22, 18, 22, 78, 98, 42, 2, 6, 22, 18, 22, 78, 98, 42, 22, 78, 98, 102, 278, 450, 322, 90, 2, 6, 22, 18, 22, 78, 98, 42, 22, 78, 98, 102, 278, 450, 322, 90, 22, 78, 98, 102, 278, 450, 322, 150, 278, 450, 502, 1038, 1906, 1866, 914, 186, 2, 6, 22, 18

Offset

0,3

Links

Robert Israel, Table of n, a(n) for n = 0..10000

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

Maple

A[0]:= 1:A[1]:= 0:
for d from 1 to 7 do
  for j from 0 to 2^d-1 do
    A[2^d+j]:= 2*A[j]+3*A[j+1]
od od:
seq(A[i], i=0..2^8-1); # Robert Israel, Mar 22 2017

Crossrefs

Sequence in context: A340857 A241040 A151705 * A229578 A078992 A062321

Adjacent sequences: A170858 A170859 A170860 * A170862 A170863 A170864

Keyword

nonn

Author

N. J. A. Sloane, Jan 02 2010

Status

approved