136.4.0.0 /20
16 subnets 14 usable
4094 hosts 4092 usable

Network.......First Host.....Last Host........Broadcast
136.4.0.0.....136.4.0.1......136.4.15.254.....136.4.15.255*
136.4.16.0....136.4.16.1.....136.4.31.254.....136.4.31.255
136.4.32.0....136.4.32.1.....136.4.47.254.....136.4.47.255
136.4.48.0....136.4.48.1.....136.4.63.254.....136.4.63.255
136.4.64.0....136.4.64.1.....136.4.79.254.....136.4.79.255
136.4.80.0....136.4.80.1.....136.4.95.254.....136.4.95.255
136.4.96.0....136.4.96.1.....136.4.111.254....136.4.111.255
136.4.112.0...136.4.112.1....136.4.127.254....136.4.127.255
136.4.128.0...136.4.128.1....136.4.143.254....136.4.143.255
136.4.144.0...136.4.144.1....136.4.159.254....136.4.159.255
136.4.160.0...136.4.160.1....136.4.191.254....136.4.191.255
136.4.192.0...136.4.192.1....136.4.223.254....136.4.223.255
136.4.224.0...136.4.224.1....136.4.239.254....136.4.239.255
136.4.240.0...136.4.240.1....136.4.255.254....136.4.255.255*

*First and Last, do not use.
**Populated segments get numbered starting at 136.4.16.0 and count up.
**Unpopulated segments get numbered starting at 136.4.224.0 and count down.
**The first 20 usable addresses on each subnet are reserved for servers, routers and other devices that require a static ip.