Language: C C++ D Haskell Lua OCaml PHP Perl Plain Text Python Ruby Scheme Tcl -- sieve of eratosthenes function primes (n) max_index = math.floor((n-1)/2) v = {} for i = 1, max_index do v[i] = true end p = 3 while p*p <= n do i = math.floor(p/2) if v[i] then for j = 2*i*(i+1), max_index, p do v[j] = false end end p = p + 2 end ps = {2} for i = 1, max_index do if v[i] then table.insert(ps, 2*i+1) end end return ps end print(#(primes(1000))) Private [?] Run code