10 FOR loop%=0 TO 20
   20  PRINT loop%,(loop%+3) AND (NOT 3)
   30 NEXT

         0         0
         1         4
         2         4
         3         4
         4         4
         5         8
         6         8
         7         8
         8         8
         9        12
        10        12
        11        12
        12        12
        13        16
        14        16
        15        16
        16        16
        17        20
        18        20
        19        20
        20        20