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Search: id:A145841
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| A145841 |
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Number of 5-compositions of n |
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+0
1
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| 1, 5, 40, 310, 2395, 18501, 142920, 1104060, 8528890, 65885880, 508970002, 3931805460, 30373291380, 234634403620, 1812556389540, 14002041536004, 108166106338760, 835585763004880, 6454920038905520, 49864411953151840
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OFFSET
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1,2
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COMMENT
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A 5-composition of n is a matrix with five rows, such that each column has at least one non zero element and whose elements sum up to n
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REFERENCES
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G. Louchard, Matrix compositions: a probabilistic approach, Proceedings of GASCom and Bijective Combinatorics 2008, Bibbiena, Italy, p. 159-170.
E. Munarini, M. Poneti and S. Rinaldi, Matrix compositions, Proceedings of Formal Power Series and Algebraic Combinatorics 2006, San Diego, USA, J. Remmel, M. Zabrocki (Eds.) 445-456.
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FORMULA
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a(n+5)=10*a(n+4)-20*a(n+3)+20*a(n+2)-10*a(n+1)+2*a(n); G.f.:(1-x)^5/(2(1-x)^5-1)
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CROSSREFS
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Cf. A003480 (2-compositions)
Sequence in context: A125729 A144069 A073505 this_sequence A123943 A067412 A078846
Adjacent sequences: A145838 A145839 A145840 this_sequence A145842 A145843 A145844
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KEYWORD
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nonn
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AUTHOR
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Simone Rinaldi (rinaldi(AT)unisi.it), Oct 21 2008
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