Answer:
2n+2 ways to win
Step-by-step explanation:
You generalize by observing patterns in the way you solve the smaller problems.
The number of winning moves is 2n+2: the total of the number of diagonals, columns, and rows.
For an n×n board, there are 2 full-length diagonals, n columns, and n rows, hence 2+n+n = 2n+2 ways to win.