7814016domain: NAppears in sequencesa(n) = n*(n+1)*(n+2)*(n+3)*(n+4)*(n+5)/5.at n=16A162669a(n) = [x^n] 24*(-40*x^4 + 49*x^3 - 15*x^2 + 13*x + 2) / (1 - 4*x)^(9/2).at n=5A344401