"""
Berechnung von Zeta(3)
(c) Jürgen Meier
www.3d-meier.de
05.07.2024
"""

import math


p = 0
k = 5
for n in range(1, k + 1):
    zaehler = ((-1.0)**(n-1))*(56*n*n - 32*n + 5)*(math.factorial(n - 1)**3)
    nenner = (2*n - 1)*(2*n - 1)*math.factorial(3*n)
    p = p + zaehler/nenner

print(p/4)