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A323092
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Number of double-free integer partitions of n.
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47
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1, 1, 2, 2, 4, 5, 7, 10, 14, 17, 24, 30, 40, 50, 66, 81, 104, 128, 161, 197, 246, 300, 369, 446, 546, 656, 796, 952, 1148, 1366, 1637, 1940, 2311, 2730, 3234, 3806, 4489, 5262, 6181, 7225, 8454, 9846, 11484, 13335, 15499, 17948, 20796, 24017, 27751, 31970, 36837
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OFFSET
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0,3
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COMMENTS
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An integer partition is double-free if no part is twice any other part.
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LINKS
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EXAMPLE
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The a(1) = 1 through a(8) = 14 double-free integer partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (111) (22) (32) (33) (43) (44)
(31) (41) (51) (52) (53)
(1111) (311) (222) (61) (62)
(11111) (411) (322) (71)
(3111) (331) (332)
(111111) (511) (431)
(4111) (611)
(31111) (2222)
(1111111) (3311)
(5111)
(41111)
(311111)
(11111111)
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MATHEMATICA
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Table[Length[Select[IntegerPartitions[n], Intersection[#, 2*#]=={}&]], {n, 30}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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