A017861 Expansion of 1/(1-x^7-x^8-x^9-x^10-x^11-x^12).

1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 2, 3, 4, 5, 6, 5, 5, 6, 8, 11, 15, 21, 25, 28, 31, 35, 41, 50, 66, 86, 108, 131, 155, 181, 210, 251, 309, 386, 482, 596, 727, 871, 1036, 1237, 1492, 1819, 2234, 2751, 3371

Offset

0,16

Comments

Number of compositions (ordered partitions) of n into parts 7, 8, 9, 10, 11 and 12. - 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 (0,0,0,0,0,0,1,1,1,1,1,1).

Formula

a(n) = a(n-7) +a(n-8) +a(n-9) +a(n-10) +a(n-11) +a(n-12) for n>11. - Vincenzo Librandi, Jun 28 2013

Mathematica

CoefficientList[Series[1 / (1 - Total[x^Range[7, 12]]), {x, 0, 70}], x] (* Vincenzo Librandi, Jun 28 2013 *)

Prog

(Magma) m:=70; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x^7-x^8-x^9-x^10-x^11-x^12))); /* or */ I:=[1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1]; [n le 12 select I[n] else Self(n-7)+Self(n-8)+Self(n-9)+Self(n-10)+Self(n-11)+Self(n-12): n in [1..70]]; // Vincenzo Librandi, Jun 28 2013
(PARI) Vec(1/(1-x^7-x^8-x^9-x^10-x^11-x^12)+O(x^99)) \\ Charles R Greathouse IV, Jun 28 2013

Crossrefs

Sequence in context: A017871 A366259 A354153 * A094700 A073635 A071532

Adjacent sequences: A017858 A017859 A017860 * A017862 A017863 A017864

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved