a(n) = 991*n^2 + 1.

Terms

a(0) =1a(1) =992a(2) =3965a(3) =8920a(4) =15857a(5) =24776a(6) =35677a(7) =48560a(8) =63425a(9) =80272a(10) =99101a(11) =119912a(12) =142705a(13) =167480a(14) =194237a(15) =222976a(16) =253697a(17) =286400a(18) =321085a(19) =357752a(20) =396401a(21) =437032a(22) =479645a(23) =524240a(24) =570817a(25) =619376a(26) =669917a(27) =722440a(28) =776945a(29) =833432