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A170929
When regarded as a triangle, the rows of A168131 converge to this sequence.
1
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
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.]
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
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 04 2010
STATUS
approved