a(n) = 6*binomial(n+1,7).

Terms

a(0) =6a(1) =48a(2) =216a(3) =720a(4) =1980a(5) =4752a(6) =10296a(7) =20592a(8) =38610a(9) =68640a(10) =116688a(11) =190944a(12) =302328a(13) =465120a(14) =697680a(15) =1023264a(16) =1470942a(17) =2076624a(18) =2884200a(19) =3946800a(20) =5328180a(21) =7104240a(22) =9364680a(23) =12214800a(24) =15777450a(25) =20195136a(26) =25632288a(27) =32277696a(28) =40347120a(29) =50086080