oo ___ \ ` \ / n \ / \n*x - 1/ /__, n = 0
Sum(n*x^n - 1, (n, 0, oo))
// x \ || -------- for |x| < 1| || 2 | || (1 - x) | || | || oo | -oo + |< ___ | || \ ` | || \ n | || / n*x otherwise | || /__, | ||n = 0 | \\ /
-oo + Piecewise((x/(1 - x)^2, |x| < 1), (Sum(n*x^n, (n, 0, oo)), True))
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