a(n) = (n+1)(n+2)^3*(n+3)^3*(n+4)(2n+5)/4320.

Terms

a(0) =1a(1) =28a(2) =300a(3) =1925a(4) =8918a(5) =32928a(6) =102816a(7) =282150a(8) =698775a(9) =1591876a(10) =3383380a(11) =6782139a(12) =12931100a(13) =23609600a(14) =41505024a(15) =70570332a(16) =116486397a(17) =187250700a(18) =293916700a(19) =451511137a(20) =680159634a(21) =1006454240a(22) =1465100000a(23) =2100881250a(24) =2970992115