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A017886 Expansion of 1/(1-x^9-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19). 1
1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 3, 4, 5, 6, 7, 8, 9, 11, 14, 16, 19, 23, 28, 34, 41, 49, 59, 72, 86, 102, 122, 146, 175, 210, 252, 303, 366, 441, 529, 635, 762, 914, 1096, 1314, 1576, 1893, 2275 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,19

COMMENTS

Number of compositions of n into parts 9, 10, 11, ..., 19. - Joerg Arndt, Oct 12 2014

LINKS

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

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

FORMULA

a(n) = a(n-9) +a(n-10) +a(n-11) +a(n-12) +a(n-13) +a(n-14) +a(n-15) +a(n-16) +a(n-17) +a(n-18) +a(n-19) for n>18. - Vincenzo Librandi, Jul 01 2013

a(n) = a(n-1) +a(n-9) -a(n-20) for n>19. - Tani Akinari, Sep 29 2014

MATHEMATICA

CoefficientList[Series[1 / (1 - Total[x^Range[9, 19]]), {x, 0, 70}], x] (* Vincenzo Librandi, Jul 01 2013 *)

PROG

(MAGMA) m:=70; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x^9-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19))); /* or */ I:=[1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2]; [n le 19 select I[n] else Self(n-9)+Self(n-10)+Self(n-11)+Self(n-12)+Self(n-13)+Self(n-14)+Self(n-15)+Self(n-16)+Self(n-17)+Self(n-18)+Self(n-19): n in [1..70]]; // Vincenzo Librandi, Jul 01 2013

CROSSREFS

Sequence in context: A011882 A025767 A091848 * A029038 A011877 A029064

Adjacent sequences:  A017883 A017884 A017885 * A017887 A017888 A017889

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 9 06:59 EDT 2020. Contains 333344 sequences. (Running on oeis4.)