Answer:
2n^2 + n - 2.
Step-by-step explanation:
n: 1 2 3 4
Term: 4 14 28 46
Common Diff 10 14 18
2nd Diff 4 4 - So the formula will contain 2n^2
2n^2 2 8 18 32
Term: 4 14 28 46
term-2n^2: 2 6 10 14
The last set is an arithmetic sequence with nth term = 2 + (n -1)*4 = n - 2.
So the formula is 2n^2 + ( n - 2)
