Unable to cast '

I'm trying to create generator of IEnumerable to set School.Foundation,

this is the Type that I'm trying to populate at the moment:

public class School
{
    public IEnumerable<int> Foundation;
}

this is my generator so far:

public static IEnumerable<T> GetEnumerable <T>(Func<T> f)
    {
        while(true)
        {
            yield return f();
        }
    }

So what I'm doing is the following reflection:

Dictionary<string, Func<object>> funcMembers;

public static object Generator(String name, Type t)
{
    Func<object> func;
    if (funcMembers.TryGetValue(name, out func))
    {
         if (t.Name.StartsWith("IEnumerable"))
             return GetEnumerable(func);
    }
}

I made the following test to check if it was fully functional:

    [TestMethod]
    public void Test_generator()
    {   
        private Dictionary<string, Func<object>> funcMembers = new Dictionary<string, Func<object>>();

        //adding the Field "Foundation" generator on the dictionary
        funcMembers.Add("Foundation", () => {return 4;}); 

        School s = new School();

        // calling my Generator that should return IEnumerable<int>
        s.Foundation = Generator(
                         "Foundation",
                          typeof(School).GetField("Foundation").

        Assert.IsNotNull(s.Foundation);
    }

i have the following error when I'm on line:

s.Foundation = Generator(
                     "Foundation",
                      typeof(School).GetField("Foundation").

the error is the following:

> Unable to cast object of type '<GetEnumerable>d__14`1[System.Object]'
> to type 'System.Collections.Generic.IEnumerable`1[System.Int32]'.