a(n) = 36*n^2 - 8*n - 2 (n >=1).

Terms

a(0) =26a(1) =126a(2) =298a(3) =542a(4) =858a(5) =1246a(6) =1706a(7) =2238a(8) =2842a(9) =3518a(10) =4266a(11) =5086a(12) =5978a(13) =6942a(14) =7978a(15) =9086a(16) =10266a(17) =11518a(18) =12842a(19) =14238a(20) =15706a(21) =17246a(22) =18858a(23) =20542a(24) =22298a(25) =24126a(26) =26026a(27) =27998a(28) =30042a(29) =32158