a(n) = 2*n*(7*n - 3).

Terms

a(0) =0a(1) =8a(2) =44a(3) =108a(4) =200a(5) =320a(6) =468a(7) =644a(8) =848a(9) =1080a(10) =1340a(11) =1628a(12) =1944a(13) =2288a(14) =2660a(15) =3060a(16) =3488a(17) =3944a(18) =4428a(19) =4940a(20) =5480a(21) =6048a(22) =6644a(23) =7268a(24) =7920a(25) =8600a(26) =9308a(27) =10044a(28) =10808a(29) =11600