3498146domain: NAppears in sequencesExpansion of (2/(3*sqrt(1-4*z)-1+4*z))*((1-sqrt(1-4*z))/(2*z))^k with k=9.at n=9A172066a(n) = Sum_{k=0..n} C(n+k,n-k)*C(2*n-k,k).at n=9A183160