The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A170840 G.f.: Product_{k>=2} (1 + x^(2^k-1) + 3x^(2^k)). 0

%I

%S 1,0,0,1,3,0,0,1,3,0,1,6,9,0,0,1,3,0,1,6,9,0,1,6,9,1,9,27,27,0,0,1,3,

%T 0,1,6,9,0,1,6,9,1,9,27,27,0,1,6,9,1,9,27,27,1,9,27,28,12,54,108,81,0,

%U 0,1,3,0,1,6,9,0,1,6,9,1,9,27,27,0,1,6,9,1,9,27,27,1,9,27,28,12,54,108,81,0

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

%H David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, 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.]

%H N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a>

%K nonn

%O 0,5

%A _N. J. A. Sloane_, Jan 02 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 25 07:22 EDT 2023. Contains 361511 sequences. (Running on oeis4.)