# -*- coding: utf-8 -*-
"""
Created on Tue Jan 20 11:41:17 2026

@author: François Coulombeau
"""

def f(x,n):
    return x**3+n*x-1

def X(n):
    return 1/n-1/n**4+3/n**7-12/n**10+55/n**13-255/n**16

for n in [3,5,10,20]:
    print(n, X(n), f(X(n),n))
    print()