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A118544 Number of subsets A of {1,2,...,n} with |A+A| = |A-A|. 6


%S 2,4,8,14,24,40,66,106,174,286,480,814,1412,2480,4476,8184,15230,

%T 28652,54488,104262,201266,390090,760234,1486030,2914492,5728506,

%U 11289420,22279222,44046072,87181188,172777354,342724456,680524908,1352154964,2688763324

%N Number of subsets A of {1,2,...,n} with |A+A| = |A-A|.

%C Keywords: sum-dominant sets, MSTD sets.

%C Some authors work with subsets of [0..n-1], others with subsets of [1..n].

%H James Wilcox and Giovanni Resta, <a href="/A118544/b118544.txt">Table of n, a(n) for n = 1..40</a> (first 35 terms from James Wilcox)

%e a(4)=14: two of the sixteen subsets of {1,2,3,4} have |A+A|<|A-A| (specifically, {1,3,4} and {1,2,4}).

%Y Cf. A222807, A222808, A140794.

%K nonn

%O 1,1

%A _Kevin O'Bryant_, May 07 2006

%E a(21)-a(29) from _Robert Gerbicz_, Nov 19 2010

%E a(30)-a(35) from _James Wilcox_, Jul 22 2013

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Last modified October 17 18:51 EDT 2019. Contains 328127 sequences. (Running on oeis4.)