

A265639


Number of binary strings of length n that cannot be written as the concatenation of nontrivial powers of other strings.


1



2, 2, 6, 10, 26, 38, 104, 162, 394, 684, 1584, 2798, 6350, 11524, 25320, 47348, 101728, 193244, 409650, 788018, 1649198, 3207640, 6648872, 13030392, 26821720, 52867234, 108207760, 214252886, 436604050, 867366654, 1761592316, 3508334870, 7106441568, 14179665756
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..34.


FORMULA

a(n) = 2^n  A265642(n).  Altug Alkan, Dec 20 2015


EXAMPLE

For n = 4 there are 16 strings of length 4, of which 4 are powers: 0000, 1111, 0101, 1010, and 2 are the products of two powers: 0011, 1100. So a(4) = 10.


CROSSREFS

Cf. A265642.
Sequence in context: A151575 A284462 A262278 * A208900 A229733 A265987
Adjacent sequences: A265636 A265637 A265638 * A265640 A265641 A265642


KEYWORD

nonn,base


AUTHOR

Jeffrey Shallit, Dec 11 2015


EXTENSIONS

a(17)a(34) from Lars Blomberg, Dec 20 2015


STATUS

approved



