a(n) = (2*n + 4)!*(n^2 + 11*n + 2)/(2*(n-1)!*(n+6)!).

Terms

a(0) =1a(1) =14a(2) =110a(3) =682a(4) =3731a(5) =18928a(6) =91392a(7) =426360a(8) =1939938a(9) =8662214a(10) =38119510a(11) =165828390a(12) =714707175a(13) =3056887680a(14) =12991772640a(15) =54919766160a(16) =231102342990a(17) =968661801900