Programmcode:
for a:50 thru 60 do block( for b:50 thru 60 do block( c:a*b/(a+b), if c=floor(c) then /* printf(true,"~{~{~9,1f ~}~%~}",args(matrix([a,b,c])))*/ printf(true,"~{~{~9,1f ~}~%~}",[[a,b,c]]) ) );
Maxima Online: http://maxima-online.org/?inc=r309228864