a(n) = binomial coefficient C(2n, n-7).

Terms

a(0) =1a(1) =16a(2) =153a(3) =1140a(4) =7315a(5) =42504a(6) =230230a(7) =1184040a(8) =5852925a(9) =28048800a(10) =131128140a(11) =600805296a(12) =2707475148a(13) =12033222880a(14) =52860229080a(15) =229911617056a(16) =991493848554