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A017831
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Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9).
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1
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1, 0, 0, 0, 1, 1, 1, 1, 2, 3, 3, 4, 6, 9, 11, 14, 19, 27, 36, 47, 63, 86, 116, 154, 206, 278, 375, 502, 672, 903, 1215, 1631, 2187, 2936, 3945, 5298, 7110, 9544, 12817, 17212, 23107, 31020, 41650, 55926, 75088, 100810
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OFFSET
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0,9
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COMMENTS
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Number of compositions (ordered partitions) of n into parts 4, 5, 6, 7, 8 and 9. - Ilya Gutkovskiy, May 25 2017
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LINKS
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FORMULA
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a(n) = a(n-4) +a(n-5) +a(n-6) +a(n-7) +a(n-8) +a(n-9) for n>9. - Vincenzo Librandi, Jun 27 2013
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MATHEMATICA
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CoefficientList[Series[1 / (1 - Total[x^Range[4, 9]]), {x, 0, 50}], x] (* Vincenzo Librandi, Jun 27 2013 *)
LinearRecurrence[{0, 0, 0, 1, 1, 1, 1, 1, 1}, {1, 0, 0, 0, 1, 1, 1, 1, 2}, 60] (* Harvey P. Dale, Oct 03 2016 *)
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PROG
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(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/ (1-x^4-x^5-x^6-x^7-x^8-x^9))); // Vincenzo Librandi, Jun 27 2013
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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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