From the series, 2, 8, 18, 32, 50,...
By observation and by trial and error.
The first term, n = 1 = 2*1*1 = 2
Second term, n =2, = 2*2*2 = 8
Third, n =3, = 2*3*3 = 18
Third term, n = 4, = 2*4*4 = 32
Fourth term, n =5, 2 * 5* 5 = 50
For nth term, 2 *n *n = 2n²
Therefore nth term = 2n²
I hope this helps.
