a(n) = (2*n - 1)*n^2.

Terms

a(0) =0a(1) =1a(2) =12a(3) =45a(4) =112a(5) =225a(6) =396a(7) =637a(8) =960a(9) =1377a(10) =1900a(11) =2541a(12) =3312a(13) =4225a(14) =5292a(15) =6525a(16) =7936a(17) =9537a(18) =11340a(19) =13357a(20) =15600a(21) =18081a(22) =20812a(23) =23805a(24) =27072a(25) =30625a(26) =34476a(27) =38637a(28) =43120a(29) =47937