The median of the three numbers, the one which appears in the middle when you place them in order, is 350.
126, 252, 378 . . .
126, 252, 378
126, 252, 378 and so on.
63, 126, 189, 252, 315, 378, 441, 504, 567, 630, 693, 756, 819, 882, 945, . . . forever
126, 252 and 378.
126, 252, 378
126, 252, 378 and so on.
126, 252, 378
126, 252, 378
126, 252, 378, 504, 630, 756, 882 . . .
42, 84, 126, 168, 210, 252, 294, 336, 378, . . .
126, 252, 378 and so on.