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Search: id:A091601
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| A091601 |
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Number of ordered partitions of n with designated summands. |
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+0
2
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| 1, 1, 3, 6, 14, 30, 69, 153, 345, 771, 1730, 3873, 8682, 19450, 43590, 97668, 218864, 490416, 1098933, 2462458, 5517870, 12364356, 27705944, 62083134, 139115247, 311727845, 698516370, 1565227653, 3507344882, 7859219406, 17610851898
(list; graph; listen)
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OFFSET
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0,3
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LINKS
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N. J. A. Sloane, Transforms
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FORMULA
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INVERT(DCONV(A000012, iINVERT(A000027)))
G.f.: 1/(1 - sum(k>0, x^k/(1-x^k+x^(2*k)))). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Dec 04 2004
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EXAMPLE
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a(3)=6 because the ordered partitions of 3 with designated summands are 3', 2'1', 1'2', 1'11, 11'1, 111'. The partition 1121 corresponds to 1'12'1' and 11'2'1'.
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CROSSREFS
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Cf. A077285.
Sequence in context: A083797 A131244 A077926 this_sequence A063119 A106803 A121514
Adjacent sequences: A091598 A091599 A091600 this_sequence A091602 A091603 A091604
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KEYWORD
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nonn
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AUTHOR
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Christian G. Bower (bowerc(AT)usa.net), Jan 23 2004
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