Find the nth term of the following sequences (i) 2, 5, 10, 17,...

Find the nth term of the following sequences
(i) 2, 5, 10, 17,...
Solution :
(1 + 1), (4 + 1), (9 + 1), (16 + 1),...
(12 + 1), (22 + 1), (32 + 1), (42 + 1),...
nth term of the sequence  :

an  = n2 + 1