3, 10, 21, 44, 65, 102, ___ ?

133.
A very tough one!
The numbers represent the odd prime numbers, multiplied by the
number for their place in the series of odd prime numbers.
3 is the first odd prime number,
& because it is first, it is multiplied by 1;

5 is the second odd prime number, & is thus multiplied by 2,
which yields 10,
& so on.