cheater00 cheater00 wrote: > +--0-+-00+-0-++0-0-0++ > -00+00---0+++0-++0---0 > 0+-000+0-0+0++-0-+00+- > .... Looks like the Moebius function (if you map "+" to "+1" and "-" to "-1"). Neil -- http://www.njohnson.co.uk