>I meant prime numbers, just didn't know the correct term. E.g. each number has only two dividors (1 and itself).
>
>1
>2
>3
>5
>7
>11
>13
>etc.
It is convenient to have a UDF that returns .T. if the input is a prime number.
An algorithm that is reasonable in terms of speed and simplicity, for numbers up to several millions, is:
Divide input by 2
Divide input by all odd numbers, from 3 to sqrt(input)
Return .F. immediately if any of the divisions gives no remainder.
You can then search for each prime number with a loop, also starting at 2, and then:
for i = 3 to MaxRange step 3
if not seek(i) and IsPrime(i)
insert into...
endif
next
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)