Repeat even numbers in an array VBA - excel

Question

I'm trying to make a macro for where a user inputs a number and the even numbers are repeated in an array. I have got the code for repeating the numbers from 0-n (n being the number inputted). However, I don't know how to go about repeating the even numbers twice.
Sub Macro3()
For n = 1 To Worksheets("Sheet1").Cells(1, 2) + 1
Cells(2, 1 + n).Select
ActiveCell.FormulaR1C1 = (n - 1)
Next
End Sub
Below is the output
Current code vs what I really want

Answer 1

Write an Array of Integers
Writes an array of integers between 0 and the specified value in cell B1 to a row range starting from B2. Even numbers are written twice (one worksheet).
Initial Solution
This is a slow solution meant to be educational in understanding object variables (workbook-worksheet-range), ranges (Resize, Offset), loops,...
Option Explicit
Sub WriteArrayOfIntegersRange()
Const ProcTitle As String = "Write Array of Integers Range"
Dim wb As Workbook: Set wb = ThisWorkbook ' workbook containing this code
Dim ws As Worksheet: Set ws = wb.Worksheets("Sheet1")
' Create a reference to the source cell.
Dim sCell As Range: Set sCell = ws.Range("B1")
' Write the value of the source cell to a variable.
Dim sValue As Variant: sValue = sCell.Value
Dim LastInteger As Long
' Validate the source cell value.
If IsNumeric(sValue) Then ' is a number
LastInteger = Abs(CLng(sValue)) ' positive ('Abs'), whole ('CLng')
Else ' is not a number
MsgBox "The value in cell '" & sCell.Address(0, 0) & "' ('" _
& sValue & "' is not a number.", vbCritical, ProcTitle
Exit Sub
End If
' Create a reference to the first destination cell.
Dim dCell As Range: Set dCell = ws.Range("B2"): dCell.Value = 0
Dim Size As Long: Size = 1
Dim n As Long
' Loop through the numbers and apply alternating row size (1 or 2)
' and column offset (2 or 1) before writing.
For n = 1 To LastInteger
Set dCell = dCell.Offset(, Size) ' define next first cell
Size = 2 - n Mod 2 ' calculate the size (Odd = 1, Even = 2)
dCell.Resize(, Size).Value = n ' write to the resized row range
Next n
' Clear the range to the right of the last cell to remove any previous data.
Dim crrg As Range
With dCell.Offset(, Size) ' define next first cell
' Define the range from the next first to the last worksheet cell
' in the row.
Set crrg = .Resize(, ws.Columns.Count - .Column + 1)
End With
crrg.Clear ' or crrg.ClearContents
MsgBox "Array of numbers written.", vbInformation, ProcTitle
End Sub
Using Arrays
This is a more advanced solution that utilizes the multi-purpose GetArrayOfIntegers function. By modifying the related constants (Function Parameters) in the following procedure, you can easily change the output.
Note that it returns the results in another worksheet (Sheet2).
The last procedure is created for anyone to quickly get a flavor of the GetArrayOfIntegers function. Just add a new workbook, add a new module and copy the codes to it. Modify the function parameters in the last procedure to get different results in the Immediate window (Ctrl+G).
Sub WriteArrayOfIntegers()
' Needs the 'GetArrayOfIntegers' function.
Const ProcTitle As String = "Write Array of Numbers"
' Source
Const sName As String = "Sheet1"
Const sCellAddress As String = "B1"
' Destination
Const dName As String = "Sheet2"
Const dfCellAddress As String = "B2"
' Function Parameters ' experiment with these five parameters
Const EvensCount As Long = 2
Const OddsCount As Long = 1
Const DoReturnRow As Boolean = True
Const IncludeZero As Boolean = True
Const IsZeroOdd As Boolean = True
' Workbook
Dim wb As Workbook: Set wb = ThisWorkbook ' workbook containing this code
' Create a reference to the source cell.
Dim sws As Worksheet: Set sws = wb.Worksheets(sName)
Dim sCell As Range: Set sCell = sws.Range(sCellAddress)
' Write the value of the source cell to a variable.
Dim sValue As Variant: sValue = sCell.Value
Dim LastInteger As Long
' Validate the source cell value.
If IsNumeric(sValue) Then ' is a number
LastInteger = Abs(CLng(sValue)) ' positive ('Abs'), whole ('CLng')
Else ' is not a number
MsgBox "The value in cell '" & sCell.Address(0, 0) & "' ('" _
& sValue & "' is not a number.", vbCritical, ProcTitle
Exit Sub
End If
' Return the result (an array) of the 'GetArrayOfIntegers' function.
Dim Data As Variant: Data = GetArrayOfIntegers( _
LastInteger, EvensCount, OddsCount, DoReturnRow, IncludeZero, IsZeroOdd)
' Without the constants it would be:
'Data = GetArrayOfIntegers(LastInteger, 2, 1, True, True, True)
If IsEmpty(Data) Then Exit Sub
Dim drCount As Long: drCount = UBound(Data, 1)
Dim dcCount As Long: dcCount = UBound(Data, 2)
' Create a reference to the first destination cell.
Dim dws As Worksheet: Set dws = wb.Worksheets(dName)
Dim dfCell As Range: Set dfCell = dws.Range(dfCellAddress)
' Clear all cells next to (to the right of) and below
' the first destination cell.
Dim dcrg As Range: Set dcrg = dfCell.Resize( _
dws.Rows.Count - dfCell.Row + 1, dws.Columns.Count - dfCell.Column + 1)
dcrg.Clear ' or dcrg.ClearContents
' Create a reference to the destination range.
Dim drg As Range: Set drg = dfCell.Resize(drCount, dcCount)
' Write the values from the array to the destination range.
drg.Value = Data
MsgBox "Array of numbers written.", vbInformation, ProcTitle
End Sub
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Author: VBasic2008
' Dates: 20211101
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Purpose: Returns an array of integers in a 2D one-based array.
' Remarks: The first element is always 0 or 1.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Function GetArrayOfIntegers( _
ByVal LastInteger As Long, _
Optional ByVal EvensCount As Long = 1, _
Optional ByVal OddsCount As Long = 1, _
Optional ByVal DoReturnRow As Boolean = False, _
Optional ByVal IncludeZero As Boolean = False, _
Optional ByVal IsZeroOdd As Boolean = False) _
As Variant
Dim eoArr() As Long: ReDim eoArr(0 To 1)
eoArr(0) = EvensCount: eoArr(1) = OddsCount
Dim zCount As Long
If IncludeZero Then
If IsZeroOdd Then zCount = OddsCount Else zCount = EvensCount
End If
Dim iMod As Long: iMod = LastInteger Mod 2
Dim eCount As Long: eCount = Int(LastInteger / 2)
Dim oCount As Long: oCount = Int(LastInteger / 2) + iMod
Dim dtCount As Long
dtCount = eCount * EvensCount + oCount * OddsCount + zCount
Dim Data As Variant
Dim dt As Long: dt = 1
Dim n As Long
Dim r As Long
If DoReturnRow Then
ReDim Data(1 To 1, 1 To dtCount)
If zCount > 0 Then
For dt = 1 To zCount: Data(1, dt) = 0: Next dt
End If
For n = 1 To LastInteger
For r = 1 To eoArr(n Mod 2)
Data(1, dt) = n
dt = dt + 1
Next r
Next n
Else
ReDim Data(1 To dtCount, 1 To 1)
If zCount > 0 Then
For dt = 1 To zCount: Data(dt, 1) = 0: Next dt
End If
For n = 1 To LastInteger
For r = 1 To eoArr(n Mod 2)
Data(dt, 1) = n
dt = dt + 1
Next r
Next n
End If
GetArrayOfIntegers = Data
End Function
' This is an unrelated example to play with.
' Note that changing the fourth parameter will make no difference since
' the results are written to the Immediate window (Ctrl+G).
Sub GetArrayOfIntegersTEST()
' Needs the 'GetArrayOfIntegers' function.
Dim Data As Variant: Data = GetArrayOfIntegers(4, 3, 2, False, False, False)
Dim r As Long, c As Long
For r = 1 To UBound(Data, 1)
For c = 1 To UBound(Data, 2)
Debug.Print Data(r, c)
Next c
Next r
End Sub

Answer 2

Fast alternative via ArrayList
Working with an ArrayList (disposing btw of methods like .Sort,.Remove, .Insert, .Reverse) may be a convenient way to manipulate array data in a very readable way. It is not part of VBA, but can be accessed easily via late binding (referring to .Net library mscorlib.dll).
Option Explicit ' code module head
Sub DoubleEvenNumbersGreaterOne()
'a) define upper limit
Dim ws As Worksheet
Set ws = Sheet1 ' << change to project's sheet Code(Name)
Dim Limit As Long
Limit = ws.Range("B1")
'b) declare ArrayList
Dim arr As Object ' late bind .Net mscorlib.dll
Set arr = CreateObject("System.Collections.ArrayList")
'c) populate list array
arr.Add 0 ' start adding with zero
Dim i As Long
For i = 1 To Limit ' loop through sequence 1:Limit
arr.Add i ' add current number
If i Mod 2 = 0 Then arr.Add i ' additional even number
Next
'd) get array
Dim a As Variant: a = arr.ToArray ' change ArrayList object to VBA array
'Debug.Print Join(a, "|") ' optional check in VB Editor's immediate window
'e) write 0-based 1-dim array to ws (here: Sheet1) or declare another target worksheet (e.g. ws2)
With ws.Range("B2")
.EntireRow = vbNullString ' empty target row
.Resize(1, UBound(a) + 1) = a ' write values into correct number of cells
End With
End Sub
A formula oriented approach // late edit as of 11/1 2021
a) A first and very elementary way would be to
enter formula =COLUMN(A1)-INT((COLUMN(A1)+2)/3) into cell B2 and to
copy into the right neighbour cells as long as you get the wanted maximum
b) Refining this approach you can code the following udf accepting the wanted maximum as argument (note that I changed the flat Column reference to a vertical Row reference to simplify calculation of the actual maxima):
Function Sequ(ByVal maxNo As Long)
Dim myFormula As String
myFormula = Replace("=ROW(1:$)-INT((ROW(1:$)+2)/3)", "$", maxNo + maxNo \ 2 + 1)
Sequ = Application.Transpose(Evaluate(myFormula))
End Function
A direct formula entry of e.g. =Sequ(10) into B2 benefitting from the newer dynamic features of vers. 2019+/MS 365 would display all (row) elements automatically in a so called spill range without need of further inputs.
Using VBA to display results in VB Editor's immediate window could be coded as follows: Debug.Print Join(Sequ(10), "|") resulting in
0|1|2|2|3|4|4|5|6|6|7|8|8|9|10|10
or to assign the results to a variable that can be used in further code.

Answer 3

Your code is really ok, just add question is number even and one more variable to see where to write. Also just change n loop from 0:
Sub Macro3()
For n = 0 To Worksheets("Sheet1").Cells(1, 2)
a = a + 1
Cells(2, 2 + a).Select
ActiveCell.FormulaR1C1 = n
'check if number is even and check if a > 1 because we don't want to repeat 0
If n Mod 2 = 0 And a > 1 Then
a = a + 1
Cells(2, 2 + a).Select
ActiveCell.FormulaR1C1 = n
End If
Next
End Sub

Answer 4

Try this code
Sub Test()
Dim v, ws As Worksheet, i As Long, ii As Long, n As Long
Set ws = ThisWorkbook.Worksheets("Sheet1")
v = ws.Range("B1").Value
If Not IsNumeric(v) Or IsEmpty(v) Then MsgBox "Must Be Number", vbExclamation: Exit Sub
ReDim a(1 To (v / 2) + v)
For i = 1 To v
If i Mod 2 = 0 Then
For ii = 1 To 2
n = n + 1: a(n) = i
Next ii
Else
n = n + 1: a(n) = i
End If
Next i
Range("C2").Resize(, UBound(a)).Value = a
End Sub