This Excel macro generates prime numbers up to a given number entered in cell C2 of the "Data" worksheet. The macro contains subroutines to initialize parameters, generate the prime numbers, and check if each number is prime. Clicking the command button runs the macro, displaying the results and showing a status message while calculations are in progress.

1. Excel Macro to generate prime numbers upto a given number Create a Macro enabled Excel sheet by name "Generating Prime numbers.xlsm", and copy the following code into the Macro.
Now rename the first sheet in the Excel as “Data” and add a Command button at the top. Link this control to the Main() procedure in the Macro.
Now enter a number in the cell “C2”. Prime numbers will be generated up to this number. Click on the command button to run the macro and check the results.
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Public next_no, last_no, i, j, k, prime_flag As Integer Public row_no, col_no, iterations, next_prime As Integer Public prime_no(5000)
Sub Main()
' Generate prime numbers up to the given number ' Set up application progress message Application.DisplayStatusBar = True Application.StatusBar = "Calculations in progress. Please wait" Application.ScreenUpdating = False Application.DisplayAlerts = False
Call init_params Call generate_primes ' Now process the first record
End Sub
Sub init_params() ' Open files Workbooks("Generating Prime numbers.xlsm").Activate Worksheets("Data").Activate last_no = Cells(2, 3) next_no = 2 iterations = 4999 For i = 0 To iterations prime_no(i) = 0 Next prime_no(1) = 2 row_no = 4

2. col_no = 2 Cells(row_no, col_no) = prime_no(1) k = 1 End Sub
Sub generate_primes() ' Generate series of prime numbers For j = 1 To iterations next_no = next_no + 1 For i = 1 To k Call check_prime If prime_flag = 0 Then i = k End If Next
If prime_flag = 1 Then col_no = col_no + 1 If col_no > 11 Then row_no = row_no + 1 col_no = 2 End If
k = k + 1 prime_no(k) = next_prime Cells(row_no, col_no) = prime_no(k) prime_flag = 0 End If
If next_no > last_no Then j = iterations End If Next End Sub
Sub check_prime() If (((Int(next_no / prime_no(i))) * prime_no(i)) - next_no) <> 0 Then next_prime = next_no prime_flag = 1 Else prime_flag = 0 End If End Sub