oo ___ \ ` \ x! ) ----------- / (x - k)!*k! /__, n = 1
Sum(factorial(x)/((factorial(x - k)*factorial(k))), (n, 1, oo))
oo*x! ----------- k!*(x - k)!
oo*factorial(x)/(factorial(k)*factorial(x - k))
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