a(n) = n*(9*n-2).

Terms

a(0) =0a(1) =7a(2) =32a(3) =75a(4) =136a(5) =215a(6) =312a(7) =427a(8) =560a(9) =711a(10) =880a(11) =1067a(12) =1272a(13) =1495a(14) =1736a(15) =1995a(16) =2272a(17) =2567a(18) =2880a(19) =3211a(20) =3560a(21) =3927a(22) =4312a(23) =4715a(24) =5136a(25) =5575a(26) =6032a(27) =6507a(28) =7000a(29) =7511