OFFSET
0,3
FORMULA
G.f.: (1-x^9) Product_{m>0} 1/(1-x^m).
a(n) ~ 3*Pi * exp(sqrt(2*n/3)*Pi) / (4*sqrt(2)*n^(3/2)) * (1 - (3*sqrt(3/2)/Pi + Pi/(24*sqrt(6)) + 9*Pi/(2*sqrt(6)))/sqrt(n) + (109/8 + 9/(2*Pi^2) + 15769*Pi^2/6912)/n). - Vaclav Kotesovec, Nov 04 2016
MAPLE
A41:= n-> `if`(n<0, 0, combinat[numbpart](n)):
a:= n-> A41(n) -A41(n-9):
seq(a(n), n=0..50);
MATHEMATICA
Table[Count[IntegerPartitions[n], _?(FreeQ[#, 9]&)], {n, 0, 50}] (* Harvey P. Dale, Oct 02 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited by Alois P. Heinz, Dec 04 2010
STATUS
approved