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

The 12th one has all the decorations because 12 is divisible by 2, 3, and 4.

Any number not divisible by 2, 3 or 4 will not have any decorations.