OFFSET
1,11
COMMENTS
The number of multinomial coefficients such that multinomial(t_1+t_2+..._+t_n,t_1,t_2,...,t_n)=10 and t_1+2*t_2+...+n*t_n=n, where t_1, t_2, ... , t_n are nonnegative integers.
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,-1).
FORMULA
a(n) = floor((n-1)*(1/9))+floor((n-1)*(1/10))-floor((1/10)*n)+floor((n-1)*(1/5))+floor((n-1)*(1/6))-floor((1/6)*n)+floor((n+1)*(1/6))-floor((1/5)*n).
G.f.: x^7*(4*x^12 +x^11 +2*x^10 +2*x^9 +2*x^8 +3*x^7 +3*x^6 +2*x^5 +3*x^4 +x^2 +x +1) / ((x -1)^2*(x +1)*(x^2 +x +1)*(x^4 -x^3 +x^2 -x +1)*(x^4 +x^3 +x^2 +x +1)*(x^6 +x^3 +1)). - Colin Barker, Mar 06 2014
EXAMPLE
The number 11 has three partitions such that a(11)=10: 1+1+1+1+1+1+1+1+1+2, 1+1+3+3+3 and 1+1+1+4+4.
MAPLE
seq(floor((n-1)*(1/9))+floor((n-1)*(1/10))-floor((1/10)*n)+floor((n-1)*(1/5))+floor((n-1)*(1/6))-floor((1/6)*n)+floor((n+1)*(1/6))-floor((1/5)*n), n=1..80)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mircea Merca, Oct 14 2013
STATUS
approved