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

P panky Jul 2011 408 16 Sep 30, 2016 #1 The coefficients of $x^9$ in the expansion of $(1+x)(1+x^2)(1+x^3)...........(1+x^{2016})$

M mathman Forum Staff May 2007 6,932 774 Sep 30, 2016 #2 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!

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!