oo ____ \ ` \ x \ 3 *x! / -------- / (x + 3)! /___, n = 1
Sum((3^x*factorial(x))/factorial(x + 3), (n, 1, oo))
x oo*3 *x! -------- (3 + x)!
oo*3^x*factorial(x)/factorial(3 + x)
x^n/n
(x-1)^n
1/2^(n!)
n^2/n!
x^n/n!
k!/(n!*(n+k)!)
csc(n)^2/n^3
1/n^2
1/n^4
1/n^6
1/n
(-1)^n
(-1)^(n + 1)/n
(n + 2)*(-1)^(n - 1)
(3*n - 1)/(-5)^n
(-1)^(n - 1)*n/(6*n - 5)
(-1)^(n + 1)/n*x^n
(3*n - 1)/(-5)^n