I have received approximately ten calls from this number, and similar numbers that are only a digit or two apart, in the last five days.  Each time it goes through to my answering machine, it turns out to be a recording that you would expect to receive if you had your receiver off the hook too long without dialing a number.  It says, "If' you'd like to make a call, please hang up and try your call again.  If you'd like to make a call and are having difficulty, dial the Operator for assistance."  Why is such a recording calling me?  This happens to me regardless of the time of day or night, even though it may have been many hours since I picked up the receiver to make a call.