To stop RANDOMBETWEEN function from recalculating

Hello All,

I am utilizing following function to randomly generate positive integer =IF(NOT(ISBLANK(B2)),RANDBETWEEN(15,1506009),"") but it keeps recalculating itself every time new number is generated.

It can be solved through the following VBA code for RAND() numbers.

Function Random()
Randomize
Random = Rnd()
End Function

But its not working for RANDBETWEEN(). I have attached a screenshot for the code explanation as well. Please help

ThanksCapture_RAND VBA Code.JPG