Find out the wrong number.
2, 5, 10, 17, 26, 37, 51

The correct option is 51.

To find the wrong number in the given sequence, let us analyze the pattern of the terms:
2, 5, 10, 17, 26, 37, 51

We can look at the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
Notice that the differences between consecutive numbers are successive odd numbers: 3, 5, 7, 9, 11.

Following this pattern, the next difference should be 13.
Therefore, the term after 37 should be:
37 + 13 = 50

Alternatively, each term in the sequence can be expressed in the form of $n^2+1$ where $n$ represents consecutive integers starting from 1:
$1^2+1=2$
$2^2+1=5$
$3^2+1=10$
$4^2+1=17$
$5^2+1=26$
$6^2+1=37$
$7^2+1=50$

Since the last term in the given sequence is 51 instead of 50, 51 is the incorrect number.