Coefficient in binomial expansion

Jul 2011
408
16
The coefficients of $x^9$ in the expansion of $(1+x)(1+x^2)(1+x^3)...........(1+x^{2016})$
 

mathman

Forum Staff
May 2007
6,932
774
9=9
1+8=9
2+7=9
3+6=9
4+5=9
1+2+6=9
1+3+5=9
2+3+4=9
8 items
Coefficient = 8.

Expansion is not binomial!