Soljan1806

xn + 1 − (x + 1)n = 2001

This is a polynomial with constant term -2002. By the rational roots theorem any solution for x must be a divisor of 2002. Also any solution has to be a solution modulo any base we choose. The only divisors of 2002 which are solutions mod 3,5, and 13 are 13 and 2002. Both give solutions but n for 2002 is 0. We can use calculus to show that any solution with x = 13 has n < 35. The only value of n which works is n = 2.