

A323539


Number of distinct sets of lengths of squares that are prefixes of a lengthn binary word.


1



1, 2, 2, 4, 4, 7, 7, 11, 11, 17, 17, 25, 25, 36, 36, 50, 50, 68, 68, 90, 90, 121, 121, 154, 154, 200, 200, 256, 256, 319, 319, 395, 395, 494, 494, 599, 599
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OFFSET

1,2


COMMENTS

A square is a nonempty block of the form XX, where X is any block.


LINKS



EXAMPLE

For n = 5, the possible sets are {2,4} (for 0000); {2} (for 0011); {4} (for 0101); and the empty set.


PROG

(C++) See Links section.
(Python)
from itertools import product
def a(n): return len(set(tuple(l for l in range(n//2) if w[l] == "0" and w[:l] == w[l+1:2*l+1]) for w in product("01", repeat=n1)))


CROSSREFS

Similar to, but not the same as A277133.


KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



