(1) (P + 1)2
(2) (p + 1)3
(3) (2p + 1)(p + 1)2
(4) p3 + (p + 1)3
Solution:
Given first term of AP, a = p2+1
Here d = 1, since integers are consecutive.
Sum of first n terms of AP, Sn = (n/2)(2a+(n-1)d)
S2p+1 = ((2p+1)/2)(2a+(2p+1-1)d)
= ((2p+1)/2)(2(p2+1)+2p)
= (2p+1)(p2+1+p)
= 2p3+p2+2p+1+2p2+p
= p3 + p3 + 3p2+ 3p +1
= p3 + (p+1)3
Hence option (4) is the answer.