I have composed a simple program to calculate the number of fractions in base form with denominators up to and including 12000, and values in the range (1/3, 1/2). The program always crashes shortly after it reaches he low 6000’s in the denominator. It uses little memory, because it just keeps count rather than saving the numbers. I have tried debugging, and using the fault finder method to no avail. I normally use Python 3x but I altered the code to run in 2x, thinking that might help.link text