a(n) = 60*binomial(3*n,n)/(n+2).

Terms

a(0) =30a(1) =60a(2) =225a(3) =1008a(4) =4950a(5) =25740a(6) =139230a(7) =775200a(8) =4412826a(9) =25564500a(10) =150225075a(11) =893246400a(12) =5364333000a(13) =32489701776a(14) =198225859050