

A222807


Number of subsets A of {0,1,...,n1} with A+A > AA.


8



0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 10, 30, 66, 144, 314, 692, 1452, 3046, 6388, 13298, 27274, 56164, 113672, 231892, 470984, 950178, 1912700, 3868034, 7772172, 15651674, 31464544, 63154106, 126603428, 254088618, 508541874, 1018817124
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OFFSET

1,15


COMMENTS

Some authors work with subsets of [0..n1], others with subsets of [1..n].
Keywords: sumdominant sets, MSTD sets.
a(1)a(21) were computed by Daniel C. R. Scheinerman, Mar 10 2013; although a(1)a(27) had been found by Kevin O'Bryant some time earlier.


LINKS



FORMULA

a(n) = Sum_{i=1..n} (ni+1)*A224893(i).


EXAMPLE

The four examples illustrating a(15)=4 are (cf. A140794):
0 2 3 7 10 11 12 14,
0 2 3 4 7 11 12 14,
0 1 2 5 9 10 12 13 14,
0 1 2 4 5 9 12 13 14.


CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



