354465254domain: NAppears in sequencesOne half of binomial coefficients binomial(2*n-8,9).at n=17A053133a(n) = (4/(n + 1)) * C(5*n, n).at n=9A124724a(n) = 5*binomial(4*n+5,n)/(4*n+5).at n=10A196678