oo ____ \ ` \ k \ (-1) 2*k + 1 / -------*x / 2*k + 1 /___, k = 0
Sum(((-1)^k/(2*k + 1))*x^(2*k + 1), (k, 0, oo))
// atan(x) \ || ------- for And(x >= -1, x <= 1)| || x | || | || oo | ||____ | x*|<\ ` | || \ k 2*k | || \ (-1) *x | || / ---------- otherwise | || / 1 + 2*k | ||/___, | \\k = 0 /
x*Piecewise((atan(x)/x, (x >= -1)∧(x <= 1)), (Sum((-1)^k*x^(2*k)/(1 + 2*k), (k, 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