a(n) = 2*(n+1)*binomial(n+3,4).

Terms

a(0) =4a(1) =30a(2) =120a(3) =350a(4) =840a(5) =1764a(6) =3360a(7) =5940a(8) =9900a(9) =15730a(10) =24024a(11) =35490a(12) =50960a(13) =71400a(14) =97920a(15) =131784a(16) =174420a(17) =227430a(18) =292600a(19) =371910a(20) =467544a(21) =581900a(22) =717600a(23) =877500a(24) =1064700a(25) =1282554a(26) =1534680a(27) =1824970a(28) =2157600a(29) =2537040