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A058961
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Number of possible sets {sum(T) : T contained in S}, where S is a multiset of elements of Z/nZ.
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1
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1, 2, 4, 8, 16, 22, 50, 65, 108, 163, 282, 343, 601, 781, 1205
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OFFSET
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1,2
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COMMENTS
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For purposes of computing further terms, note that it suffices to consider multisets S having at most n-1 elements.
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LINKS
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EXAMPLE
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Consider n = 3; then the multiset {0} has 0 as the sum of any subset; {1} has a subset with sum 0 (the empty set) and one with sum 1; {2} has one with sum 0 and one with sum 2; {1,1} has sums 0, 1 and 2 represented. Thus {0}, {0,1}, {0,2}, {0,1,2} are possible values for the set of subset sums (mod 3). Conversely, any S has a subset whose sum is 0 (viz. the empty set), so these are all the possible sets of subset sums; there are 4 of them.
Note that n = 6 is the smallest value for which there exists a subset of Z/nZ, containing 0, which is not a set of subset sums.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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Gabriel D. Carroll (gastropodc(AT)hotmail.com), Jan 13 2001
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EXTENSIONS
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STATUS
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approved
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