a(n) = (3*n+1)*(4*n+1).

Terms

a(0) =1a(1) =20a(2) =63a(3) =130a(4) =221a(5) =336a(6) =475a(7) =638a(8) =825a(9) =1036a(10) =1271a(11) =1530a(12) =1813a(13) =2120a(14) =2451a(15) =2806a(16) =3185a(17) =3588a(18) =4015a(19) =4466a(20) =4941a(21) =5440a(22) =5963a(23) =6510a(24) =7081a(25) =7676a(26) =8295a(27) =8938a(28) =9605a(29) =10296