note tall_man If you want a pure iterative solution, you could compute a factor wheel and print everything but the usual trial divisors. The code looks messier, but it requires no mod calculations in the loop, just adds. I computed the wheel using [cpan://Math::Big::Factors] (so for people following the original articles, we have come full circle...). <p><readmore> <code> use strict; sub limit_print { my (\$count,@lst) = @_; return if \$count <= 0; if (@lst <= \$count) { print join(" ",@lst,""); } else { print join(" ",@lst[0..\$count-1],""); } } # factor wheel for 2,3,5 my @add = (2,2,4,2,4,2,4,6,2,6,4,2,4,2,4,6,2); # wheel restart point. my \$ws = 9; my \$we = scalar @add - 1; my @lst = (2,3,4,5); my \$count = \$ARGV; limit_print(\$count, @lst); \$count -= @lst; if (\$count <= 0) { print "\n" if \$count > -4; exit(0); } my \$lastskip = 5; my \$place = 6; my \$w = 1; while (\$count > 0) { # find the next nonmultiple of 2,3, and 5. my \$nextskip = \$lastskip + \$add[\$w]; my @lst = (\$place..\$nextskip-1); limit_print(\$count, @lst); \$count -= @lst; \$place = \$nextskip+1; \$lastskip = \$nextskip; \$w = \$ws if \$w++ == \$we; } print "\n"; </code> 440531 440547