Respuestas

2013-06-27T17:14:24+02:00
8= 16, 24, 32, 40, 48, 56, 64, 72, ...
13= 26, 39, 52, 65, 78....
21= 42, 63, 84, 105, 126...
30= 60, 90, 120, 150, 180, 210...
18= 36, 54, 72, 90, 108