Ash script to random select from an array of 2.4ghz centre frequencies

so the hostapd_cli channel change works well even in mid rsync stream, so I am thinking channel hopping might aid in messing with heads of any hackers....

so a little script to channel hop to a random entry of array of the 2.4ghz centre channels at a random time (at random beacons delay) is what I want, but this is ash, so no bash tutorial helps....