Find the nth term of the following sequences

Question 1:

2,8,18,32,50
2n2

Question 2:

3,12,27,48,75
3n2

Question 3:

2,11,26,47,74
3n21

Question 4:

-4,8,28,56,92
4n28

Question 5:

7,9,13,19,27
n2n+7

Question 6:

-8,-9,-8,-5,0
n24n5