Calculating Anti-Primes

[Kernelpanic]

while I am an advocate for explicit variable declaration, your program David, runs almost 3 times faster with DefLng A-S than with option _explicit and Dim As Long i, iq, j, isum, jk, kmax, knum, k

I don't think that's the reason for the speed increase. A test with and without $Console already shows different times.
The results are peculiar. Without "Print knum" only half the time as with?