Euler 29

    //F#:
    open System
    let mutable result = [4.0]
    let problem29 a =
        for i in [2.0..a] do
            for e in [2.0..a] do
                result <- Math.Pow(i, e)::result  
        Seq.distinct result |> Seq.length;;
    
    //C#:
    class Program
    {
        static void Main(string[] args)
        {
            var timer = new Stopwatch();
            timer.Start();

            var firstList = new List<double>();
            
            Enumerable
                .Range(2, 99)
                .ToList()
                .ForEach(i => Enumerable
                    .Range(2, 99)
                    .ToList()
                    .ForEach(e => firstList.Add(Math.Pow(i, e))));

            Console.WriteLine(firstList.Distinct().ToList().Count);

            timer.Stop();


            Console.WriteLine(@"Euler 29 took {0}ms to solve.", timer.ElapsedMilliseconds);
            Console.ReadKey();
        }
    }

Distinct powers
Problem 29
Consider all integer combinations of ab for 2 ≤ a ≤ 5 and 2 ≤ b ≤ 5:

22=4, 23=8, 24=16, 25=32
32=9, 33=27, 34=81, 35=243
42=16, 43=64, 44=256, 45=1024
52=25, 53=125, 54=625, 55=3125
If they are then placed in numerical order, with any repeats removed, we get the following sequence of 15 distinct terms:

4, 8, 9, 16, 25, 27, 32, 64, 81, 125, 243, 256, 625, 1024, 3125

How many distinct terms are in the sequence generated by ab for 2 ≤ a ≤ 100 and 2 ≤ b ≤ 100?