Complete the series: $2,5,10,17,\dots$

Let's analyze the difference between consecutive terms in the series:
* $5-2=3$
* $10-5=5$
* $17-10=7$

The differences form an arithmetic sequence of consecutive odd numbers: $3,5,7,\dots$
The next odd number difference must be $9$.
Therefore, the next term is:

$$17+9=26$$

Alternatively, the pattern follows $n^2+1$ starting from $n=1$:

* $1^2+1=2$
* $2^2+1=5$
* $3^2+1=10$
* $4^2+1=17$
* $5^2+1=26$