a(n) = n^2*(2*n^2-23).

Terms

a(0) =-21a(1) =-60a(2) =-45a(3) =144a(4) =675a(5) =1764a(6) =3675a(7) =6720a(8) =11259a(9) =17700a(10) =26499a(11) =38160a(12) =53235a(13) =72324a(14) =96075a(15) =125184a(16) =160395a(17) =202500a(18) =252339a(19) =310800a(20) =378819a(21) =457380a(22) =547515a(23) =650304a(24) =766875a(25) =898404a(26) =1046115a(27) =1211280a(28) =1395219a(29) =1599300