a(n) = binomial(n+3,3)*binomial(n+7,3).

Terms

a(0) =35a(1) =224a(2) =840a(3) =2400a(4) =5775a(5) =12320a(6) =24024a(7) =43680a(8) =75075a(9) =123200a(10) =194480a(11) =297024a(12) =440895a(13) =638400a(14) =904400a(15) =1256640a(16) =1716099a(17) =2307360a(18) =3059000a(19) =4004000a(20) =5180175a(21) =6630624a(22) =8404200a(23) =10556000a(24) =13147875a(25) =16248960a(26) =19936224a(27) =24295040a(28) =29419775