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Search: id:A077047
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| A077047 |
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Doubly restricted composition numbers: number of compositions of [n(n+2)/2] into exactly n positive integers each no more than n+1. |
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+0
5
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| 1, 1, 3, 12, 85, 780, 9331, 134512, 2306025, 45433800, 1018872811, 25506741084, 707972099627, 21518492021208, 712601187601395, 25491847538274240, 981272544393935569, 40392787067756440272, 1772592132899627652691
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OFFSET
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0,3
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LINKS
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Index entries for sequences related to compositions
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FORMULA
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a(n) =A077042(n+1, n).
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EXAMPLE
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a(3)=12 since the compositions of [3*5/2]=7 into exactly 3 positive integers each no more than 4 are: 1+2+4, 1+3+3, 1+4+2, 2+1+4, 2+2+3, 2+3+2, 2+4+1, 3+1+3, 3+2+2, 3+3+2, 4+1+2, 4+2+1.
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CROSSREFS
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Cf. A077042, A077045, A077046, A077048.
Sequence in context: A147835 A032183 A070825 this_sequence A074505 A039305 A124191
Adjacent sequences: A077044 A077045 A077046 this_sequence A077048 A077049 A077050
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KEYWORD
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nonn
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AUTHOR
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Henry Bottomley (se16(AT)btinternet.com), Oct 22 2002
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