a(n) = (n+3)*binomial(n+8, 8)/3.

Terms

a(0) =1a(1) =12a(2) =75a(3) =330a(4) =1155a(5) =3432a(6) =9009a(7) =21450a(8) =47190a(9) =97240a(10) =189618a(11) =352716a(12) =629850a(13) =1085280a(14) =1812030a(15) =2941884a(16) =4657983a(17) =7210500a(18) =10935925a(19) =16280550a(20) =23828805a(21) =34337160a(22) =48774375a(23) =68368950a(24) =94664700a(25) =129585456a(26) =175509972a(27) =235358200a(28) =312690180a(29) =411818880