9514 1404 393
Answer:
an = 2n^2
Explanation:
First differences are ...
8 -2 = 6
18 -8 = 10
32 -18 = 14
50 -32 = 18
And second differences are constant at 4:
10 -6 = 14 -10 = 18 -14 = 4
This means the sequence can be described by a degree 2 polynomial. The coefficient of the n^2 term is half the second difference: 2. We find nothing else needs to be added to the squared term.
an = 2·n^2