so here what i want to integrate
$$ r(x)= \frac{n!}{(x(x + 1).....(x + n))} $$ and here what i have done, i will thankful for tips
i have started with partial fractions $$ r(x) = \frac{A_0}{x} + \frac{A_1}{x+1}+\frac{A_2}{x+2} + ... +\frac{A_n}{x+n} $$
then i get $$ n! = A_0(x+1)(x+2)...(x+n)+A_1 x(x+2)...(x+n) + A_2 x(x+1)(x+3)...(x+n) + ... + A_n x(x+1)(x+2)...(x+n-1) $$ here were i stuck and i don't know how to continue, how to find the value of A so i could easliy then integrate the function