OFFSET
0,9
COMMENTS
Number of partitions of n into parts 1, 8, 9, and 12. - Joerg Arndt, Jul 04 2014
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (1, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 1, -1, 0, 0, 0, -1, 1, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 1, -1).
MAPLE
# this requires Maple 17 or later
N:= 10000: # to get a(0) to a(N)
with(SignalProcessing):
A1:= Array(0..N, 1):
A8:=Array(0..N, i -> `if`(i mod 8 = 0, 1, 0)):
A9:=Array(0..N, i -> `if`(i mod 9 = 0, 1, 0)):
A12:= Array(0..N, i -> `if`(i mod 12 = 0, 1, 0)):
B:= Convolution(A1, A8)[1..N+1]:
B:= Convolution(B, A9)[1..N+1]:
B:= Convolution(B, A12)[1..N+1]:
A:= map(round, ArrayTools:-Reshape(B, 0..N)):
seq(A[n], n=0..N); # Robert Israel, Jun 03 2014
MATHEMATICA
CoefficientList[Series[1/((1-x)*(1-x^8)*(1-x^9)*(1-x^12)), {x, 0, 20}], x] (* Vaclav Kotesovec, Jul 04 2014 *)
PROG
(Maxima) a(n):=floor((2*n^3+90*n^2+21*n+13023)/10368+(n+15)*(-1)^n/384 +((n+10)*(1-(-1)^n)/2+5)*((-1)^floor(n/2))/96 +(floor(n/3) -floor((n-1)/3))*(n+3)/108 +(floor((n+2)/9) +floor((n+1)/9) +floor(n/9))/3)$ makelist(a(n), n, 0, 10000); /* Tani Akinari, Jul 03 2014 */
(Magma) m:=70; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-x^8)*(1-x^9)*(1-x^12)))); // Bruno Berselli, Jul 04 2014
(Sage) m = 70; L.<x> = PowerSeriesRing(ZZ, m); f = 1/((1-x)*(1-x^8)*(1-x^9)*(1-x^12)); print(f.coefficients()) # Bruno Berselli, Jul 04 2014
(PARI) Vec(1/((1-x)*(1-x^8)*(1-x^9)*(1-x^12)) + O(x^70)) \\ Michel Marcus, Jul 04 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 11 1999
STATUS
approved