a(n) = n*(n+1)*(n+2)*(n+3)*(3*n+2)/120.

Terms

a(0) =0a(1) =1a(2) =8a(3) =33a(4) =98a(5) =238a(6) =504a(7) =966a(8) =1716a(9) =2871a(10) =4576a(11) =7007a(12) =10374a(13) =14924a(14) =20944a(15) =28764a(16) =38760a(17) =51357a(18) =67032a(19) =86317a(20) =109802a(21) =138138a(22) =172040a(23) =212290a(24) =259740a(25) =315315a(26) =380016a(27) =454923a(28) =541198a(29) =640088