"""
Berechnung von Zeta(7)
(c) Jürgen Meier
www.3d-meier.de
11.07.2024
"""

import math


a = 0
b = 0
c = 0
aa = 304/13.0
bb = -103/4.0
cc = 19/52.0

n = 7

k = 7

for i in range(1, k + 1):
    a = a + 1.0/((i**n)*(math.exp(1*math.pi*i)-1))
    b = b + 1.0/((i**n)*(math.exp(2*math.pi*i)-1))
    c = c + 1.0/((i**n)*(math.exp(4*math.pi*i)-1))

print(aa*a + bb*b + cc*c)