Ok, this can't be the solution! :)
Looking at the numbers, we can see they somehow follow the order T - F - S:
Twenty one
Forty five
Sixty six
One hundred and two
One hundred and fifteen
One hundred and seventy one
If we do not count the hundreds as part of the story, the number in the sequence would begin with an unused T, leaving us with 212.
Or 250 if we count the T of the TWO hundred.
Whatever.
Strange
