#!/usr/bin/perl
use warnings;
use strict;

sub NEXT ($) { $_[0]->() }

sub prime_iterator {
    my $num = 0;
    sub {
        do {
            $num++;
        } until ( (1 x $num) !~ /^(11+)\1+$/);
        return $num;
    }
}

my $prime = prime_iterator;
print NEXT $prime, "\n" for (1 .. shift || 10);