641277domain: NAppears in sequencesNumber of tree-rooted planar maps with 3 faces and n vertices and no isthmuses.at n=25A006470Number of arrangements of n indistinguishable balls in n boxes with the maximum number of balls in any box equal to n-4.at n=22A180294a(n) = 3^n * [x^n] Product_{k>=1} 1/(1 - 3*x^k)^(1/3).at n=7A370710