# BASH, 154 bytes File `x.bash` (no trailing newline): a=2;while((l<$1));do if [ -n "${b[a]}" ] then((c=${b[a]}));else((c=a,l++));echo $a;fi;((d=a+c)) while [ -n "${b[d]}" ];do((d+=c));done Run: $ bash x.bash 5 2 3 5 7 11 $ bash x.bash 1000 | wc -l 1000 ---- Primes get calculated by letting known primes jump on the tape of positive integers. Basically it is a serialised Sieve Of Eratosthenes. I don't have any idea about the O(n)... up to now....