507600domain: NAppears in sequencesG.f.: A(x) = 1+x*(1+2x*(1+3x*(...(1+n*x*(...)^3)^3...)^3)^3)^3.at n=6A128319Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,1,0,0,0 for x=0,1,2,3,4.at n=12A197470