my @arr = (1,2,3,4,5,6);
             #   #   #

# I would like to return 

$VAR = [2,4,6];

##</code><code>##

my @arr = (0,3,4,5,8,10,12,15);
             #   #   #     #

# I would like to return 

$VAR = [3,5,10,15];