What is the coefficient of x3x^3x3 in the product (∑n=0∞xn)(∑n=0∞xnn!)\left(\sum_{n=0}^{\infty} x^n\right) \left(\sum_{n=0}^{\infty} \frac{x^n}{n!}\right)(∑n=0∞xn)(∑n=0∞n!xn)?
166\frac{16}{6}616
53\frac{5}{3}35
83\frac{8}{3}38
106\frac{10}{6}610