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A116901
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Number of partitions of n into at least two parts such that the product of largest and smallest part does not exceed n.
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2
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0, 1, 2, 4, 5, 8, 12, 18, 25, 35, 47, 66, 87, 118, 155, 207, 264, 348, 443, 571, 725, 923, 1155, 1466, 1821, 2275, 2821, 3501, 4293, 5307, 6477, 7933, 9658, 11750, 14198, 17251, 20746, 24986, 30009, 36024, 42983, 51446, 61176, 72839, 86497, 102538
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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EXAMPLE
| a(4)=4 since property holds for 4 partitions of 4: (3,1), (2,2), (2,1,1), (1,1,1,1).
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MATHEMATICA
| (* first do *) Needs[DiscreteMath`Combinatorica`] ( then *) f[n_] := Length@ Select[ Partitions@n, (Length@ # > 1 && Last@# First@# <= n) &]; Array[f, 46] - Robert G. Wilson v (rgwv(at)rgwv.com), Mar 15 2006
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CROSSREFS
| Cf. A000041, A116900, A116902.
Sequence in context: A102186 A039842 A188216 * A102829 A031988 A023745
Adjacent sequences: A116898 A116899 A116900 * A116902 A116903 A116904
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KEYWORD
| nonn
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AUTHOR
| Giovanni Resta (g.resta(AT)iit.cnr.it), Mar 14 2006
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Mar 15 2006
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