use strict; use warnings;

my $n = 5;
for (my $i=0; $i<=$n; ++$i ) {
    print "   " x ($n-$i);
    print "/$i\\   " for 0..$i;
    print "\n";
    print "   " x ($n-$i);
    print "\\$_/   " for 0..$i;
    print "\n\n";
}