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A094367
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a(n) = the number of numerical semigroups with three generators and Frobenius number n.
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2
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1, 1, 1, 1, 3, 1, 5, 2, 4, 4, 7, 1, 11, 7, 5, 7, 14, 5, 17, 6, 9, 16, 21, 2, 19, 15, 19, 10, 28, 6, 32, 12, 30, 23, 27, 5, 48, 29, 28, 12, 46, 11, 56, 19, 35, 40, 58, 10, 58, 24, 44, 30, 76, 16, 49, 23, 56, 46, 76, 7, 98, 46, 53, 34, 67, 21, 111, 43, 82, 40, 94, 11, 119, 49
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OFFSET
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1,5
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COMMENTS
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A numerical semigroup is a set of natural numbers closed under addition. Its Frobenius number is the largest number not in it.
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LINKS
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EXAMPLE
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a(10)=4 because there are four such semigroups with Frobenius number 10. Their complements (and a generating triple) are: {1,2,3,5,6,10} (4,7,9); {1,2,3,5,6,9,10} (4,7,13); {1,2,4,5,7,10} (3,8,13); {1,2,4,5,7,8,10} (3,11,13).
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Talia Harrell (zeta_lady01(AT)yahoo.com), Apr 27 2004
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EXTENSIONS
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STATUS
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approved
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