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

use Net::IP::AddrRanges;
use Net::CIDR::Lite;

our @ip = qw(10.144.128.0/18 10.144.192.0/19 10.144.224.0/20 10.144.240.0/21 10.144.248.0/22 10.144.252.0/23 10.144.254.0/24 10.144.255.0/25 10.144.255.128/26 10.144.255.192/27 10.144.255.224/28 10.144.255.240/29 10.144.255.248/30 10.144.255.252/31 10.144.255.254/32);

my $ranges = Net::IP::AddrRanges->new();
$ranges->add(@ip);

my @ranges = $ranges->list_ranges;
if ( 1 == @ranges ) {   # good, we only expected a single range
    if ( "254" eq substr( $ranges[0], -3, 3 ) ) {
        $ranges->add( substr( $ranges[0], 0, -3 ) . '255' );
    }
}


my $cidr = Net::CIDR::Lite->new;
$cidr->add_range( $_ ) for $ranges->list_ranges;

print join "\n", $cidr->list(), "";

__END__

Result:
10.144.128.0/17