oo ___ \ ` \ -1 - n / -2 *sin(n*a) /__, n = 0
Sum((-(1/2)^(n + 1))*sin(n*a), (n, 0, oo))
oo ___ \ ` \ -1 - n / -2 *sin(a*n) /__, n = 0
Sum(-2^(-1 - n)*sin(a*n), (n, 0, oo))
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