Imports System
Imports System.Linq
Module Program
Sub Main(args As String())
Dim letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray()
Dim sequence = From one In letters
From two In letters
From three In letters
From four In letters
Order By one, two, three, four
Select New String({one, two, three, four})
' Print first 20 sequences
For Each s In sequence.Take(20)
Console.WriteLine(s)
Next
Console.WriteLine("...")
Console.WriteLine("Total sequence size: " & sequence.Count())
End Sub
End Module
' run:
'
' AAAA
' AAAB
' AAAC
' AAAD
' AAAE
' AAAF
' AAAG
' AAAH
' AAAI
' AAAJ
' AAAK
' AAAL
' AAAM
' AAAN
' AAAO
' AAAP
' AAAQ
' AAAR
' AAAS
' AAAT
' ...
' Total sequence size: 456976
'
