a(n)= numerator of ((n + 3)! - (n - 3)!)/(n!).

Terms

a(0) =719a(1) =5039a(2) =20159a(3) =60479a(4) =151199a(5) =332639a(6) =665279a(7) =1235519a(8) =2162159a(9) =3603599a(10) =5765759a(11) =8910719a(12) =13366079a(13) =19535039a(14) =27907199a(15) =39070079a(16) =53721359a(17) =72681839a(18) =96909119a(19) =127511999a(20) =165765599a(21) =213127199a(22) =271252799a(23) =342014399a(24) =427517999