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Search: id:A079122
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| A079122 |
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Number of ways to partition 2*n into distinct positive integers not greater than n. |
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5
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| 1, 0, 0, 1, 1, 3, 5, 8, 13, 21, 31, 46, 67, 95, 134, 186, 253, 343, 461, 611, 806, 1055, 1369, 1768, 2270, 2896, 3678, 4649, 5847, 7325, 9141, 11359, 14069, 17367, 21363, 26202, 32042, 39068, 47512, 57632, 69728, 84167, 101365, 121801, 146053, 174777
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OFFSET
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0,6
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FORMULA
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a(n) = b(0, n), b(m, n) = 1 + sum(b(i, j): m<i<j<n & i+j=2*n).
Coefficient of x^(2*n) in Product_{k=1..n} (1+x^k). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Aug 07 2003
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EXAMPLE
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a(4)=1 [1+3+4=2*4]; a(5)=3 [1+2+3+4=1+4+5=2+3+5=2*5].
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CROSSREFS
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Cf. A035294, A079126, A000009, A079124, A079125, A067953.
Sequence in context: A035424 A099351 A080614 this_sequence A071679 A020701 A024885
Adjacent sequences: A079119 A079120 A079121 this_sequence A079123 A079124 A079125
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Dec 27 2002
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