Find the term that comes next in the series:
\text{Z676, X576, U441, Q289, L144, \_\_\_\_\_\_}}

Let's split each term into its letter component and numeric component:
Letter tracking: $\text{Z, X, U, Q, L, ?}$
Alphabetical ranks: $\text{Z}=26$, $\text{X}=24$, $\text{U}=21$, $\text{Q}=17$, $\text{L}=12$.
Let's see the differences:

$$26-2=24(\text{X})$$

$$24-3=21(\text{U})$$

$$21-4=17(\text{Q})$$

$$17-5=12(\text{L})$$

Following this pattern, the next step should decrease by $6$:

$$12-6=6(\text{Letter F})$$

Numeric tracking: $676,576,441,289,144,?$
Notice that each number corresponds to the square of the alphabetical rank of its paired letter:

$$26^2=676$$

$$24^2=576$$

$$21^2=441$$

$$17^2=289$$

$$12^2=144$$

For the next letter $\text{F}$ (rank $6$):

$$6^2=36$$

Combining both components gives $\text{F36}$.