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A017831 Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,9

COMMENTS

Number of compositions (ordered partitions) of n into parts 4, 5, 6, 7, 8 and 9. - Ilya Gutkovskiy, May 25 2017

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,0,0,1,1,1,1,1,1).

FORMULA

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

MATHEMATICA

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 *)

PROG

(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

CROSSREFS

Sequence in context: A091275 A046936 A187067 * A132289 A078467 A154217

Adjacent sequences:  A017828 A017829 A017830 * A017832 A017833 A017834

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified October 21 11:29 EDT 2019. Contains 328295 sequences. (Running on oeis4.)