Find the nth term of the following sequences

Question 1:

4,16,36,64,100
4n2

Question 2:

3,12,27,48,75
3n2

Question 3:

-6,0,10,24,42
2n28

Question 4:

5,11,21,35,53
2n2+3

Question 5:

2,8,16,26,38
n2+3n2

Question 6:

-5,-2,5,16,31
2n23n4