Project Euler 29

Problem 29

using System;
using System.Collections.Generic;
using System.Numerics;

class PE029 {
    static void Main() {
        var st = new HashSet<BigInteger>();
        for (int i = 2; i <= 100; i++) {
            BigInteger a = i;
            for (int j = 2; j <= 100; j++) {
                st.Add(BigInteger.Pow(a, j));
            }
        }
        Console.WriteLine(st.Count);
    }
}