use strict;
my $initValue = 3;
my $step = 3;
my $numOfMembers = 25;
my $str = "";
my $ix;
for($ix = $initValue;
    $ix <= $initValue + $step * ($numOfMembers - 1);
    $ix += $step)
{
    $str .= $str eq "" ? $ix : " $ix";
}
### TEST ###
print "'$str'\n";