New in version 2.0.
True when expr is equivalent to a positive integer and can be written with zero or more dots:
abjad> from abjad.tools import mathtools
abjad> for expr in range(16):
... print '%s %s' % (expr, mathtools.is_dotted_integer(expr))
...
0 False
1 False
2 False
3 True
4 False
5 False
6 True
7 True
8 False
9 False
10 False
11 False
12 True
13 False
14 True
15 True
Otherwise false.
Return boolean.
Integer n qualifies as dotted when abs(n) is of the form 2**j * (2**k - 1) with integers 0 <= j, 2 < k.