a(n) = 841*n^2 + 2*n.

Terms

a(0) =843a(1) =3368a(2) =7575a(3) =13464a(4) =21035a(5) =30288a(6) =41223a(7) =53840a(8) =68139a(9) =84120a(10) =101783a(11) =121128a(12) =142155a(13) =164864a(14) =189255a(15) =215328a(16) =243083a(17) =272520a(18) =303639a(19) =336440a(20) =370923a(21) =407088a(22) =444935a(23) =484464a(24) =525675a(25) =568568a(26) =613143a(27) =659400a(28) =707339a(29) =756960