[deegu]

if you run it with luajit -jv primes.lua you'll see NYIs about math.mod not implemented.

Replacing math.mod(n, i) with (n % i) gives roughly 9.4x performance.

EDIT: luajit version was LuaJIT 2.0.4 on Mac OSX

[ryanmk]

Thanks, using % did the trick.