A170929 When regarded as a triangle, the rows of A168131 converge to this sequence.

1, 4, 5, 3, 7, 17, 17, 7, 6, 13, 13, 13, 32, 55, 45, 15, 6, 13, 13, 13, 31, 51, 41, 20, 25, 39, 39, 58, 120, 159, 109, 31, 6, 13, 13, 13, 31, 51, 41, 20, 25, 39, 39, 58, 119, 155, 105, 36, 25, 39, 39, 57, 113, 143, 102, 65, 89, 117, 136, 236, 400, 431, 253, 63, 6, 13, 13, 13, 31

Offset

0,2

Links

Table of n, a(n) for n=0..68.

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

Sequence in context: A004493 A348051 A328238 * A245085 A299420 A374677

Adjacent sequences: A170926 A170927 A170928 * A170930 A170931 A170932

Keyword

nonn

Author

N. J. A. Sloane, Feb 04 2010

Status

approved