Floyd's Triangle

Module floyds_tri
    Sub Main()
        Dim i, j, s, n As Integer
        Console.Write("Enter the number of lines:")
        n = CInt(Console.ReadLine())
        s = 1
        For i = 1 To n
            For j = 1 To i
                Console.Write(s & " ")
                s += 1
            Next

            Console.WriteLine()
        Next
        Console.ReadLine()
    End Sub
End Module

Output

1

2  3

4  5  6

7  8  9  10

11 12 13 14 15