Behold! A New Number Series

Actually, it may not be new, but I discovered it and I hope nobody else did.
This yet unnamed subset of integers have the property where clumps of digits must be half or double neighboring digits. So for example, 2040, 48, and 63 are members. 17 and 94 are not. Here are the ones that corresponding to ages:

12
21
24
36
42
48
63
84
105