identify and return row and column number of cell

I understand 1,1,2,8 for A.
But why 2,2,4 for B?

Sub test()
    Dim i As Long, x
    Cells(1).CurrentRegion.Offset(1).ClearContents
    For i = 1 To Cells(1).CurrentRegion.Columns.Count
        x = [a17].CurrentRegion.Address
        x = Split(Evaluate("textjoin(char(2),true,transpose(if(" & x & "=""" & _
        Split(Cells(1, i))(0) & """,column(" & x & "),"""")))"), Chr(2))
        If UBound(x) > -1 Then Cells(2, i).Resize(UBound(x) + 1) = Application.Transpose(x)
    Next
End Sub