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A245370
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Number of compositions of n into parts 3, 5 and 9.
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0
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1, 0, 0, 1, 0, 1, 1, 0, 2, 2, 1, 3, 3, 3, 6, 5, 6, 11, 10, 13, 19, 19, 27, 35, 37, 52, 65, 74, 100, 121, 145, 192, 230, 282, 365, 440, 548, 695, 843, 1058, 1327, 1621, 2035, 2535, 3119, 3910, 4851, 5997, 7503, 9297, 11528, 14389, 17829, 22150, 27596, 34208, 42536, 52928, 65655, 81660, 101525, 126020, 156738, 194776, 241888
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OFFSET
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0,9
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LINKS
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FORMULA
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G.f.: 1/(1-x^3-x^5-x^9).
a(n) = a(n-3) + a(n-5) + a(n-9).
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EXAMPLE
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a(28)=100 The compositions of n into parts 3,5 and 9 are the permutations of (9955)(these are 4!/2!2!=6), (555553) (these are 6!/5!=6), (955333) (these are 6!/3!2!=60), (55333333) (these are 8!/6!2!=28).
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PROG
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(PARI) Vec( 1/(1-x^3-x^5-x^9) +O(x^66) ) \\ Joerg Arndt, Aug 24 2014
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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