vb.net pascal triangle

Public Class Form1
    Function pascal(ByVal floor As Integer) As String
        Dim ar1 = New Integer() {1, 1}
        If floor < 2 Then
            Return "1 1"


        End If
        Return pascalPt2(floor, 2, ar1)
    End Function
    Function pascalPt2(ByVal floor As Integer, ByVal at As Integer, ByVal prevfloor As Object) As String
        Dim result = ""
        Dim ar2(at) As Integer
        ar2(0) = 1
        If at = floor + 1 Then
            For Each item As Integer In prevfloor
                result &= item.ToString() & " "

            Next
            Return result
        Else
            For index = 0 To at - 2
                ar2(index + 1) = prevfloor(index) + prevfloor(index + 1)
            Next
            ar2(at) = 1
        End If
        Return pascalPt2(floor, at + 1, ar2)
    End Function
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        MsgBox(pascal(4))
    End Sub
End Class