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

Author

N. J. A. Sloane, Feb 04 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

Formula

Sum_{i=0 .. 2^k - 1} a(i) = 4^i - 2^i - 2 for k >= 2 (cf. A170940).