The items in the sequence should be numbered from 2 onwards, and then item $b$ is

>! the base-$b$ representation of $\displaystyle \left \lfloor \frac{b^2}{4} \right \rfloor$, which can also be written as just $\displaystyle \left \lfloor \frac{100}{4} \right \rfloor$, since $b$ in base $b$ is always $10$.

So the fraction that defines the sequence is

>! **100/4**

and the next few entries in the sequence are:

>! 30, 33, 37, 3B, 40, 44, 49, 4E, 50.