a(n) = binomial coefficient C(2n, n - 8).

Terms

a(0) =1a(1) =18a(2) =190a(3) =1540a(4) =10626a(5) =65780a(6) =376740a(7) =2035800a(8) =10518300a(9) =52451256a(10) =254186856a(11) =1203322288a(12) =5586853480a(13) =25518731280a(14) =114955808528a(15) =511738760544