3120041domain: NAppears in sequencesExpansion of -(2*x^3-x^2+x-1)/(x^4-3*x^3+3*x^2-3*x+1).at n=20A013326Number of nX5 0..1 arrays with every element equal to 1, 2, 4, 6, 7 or 8 king-move adjacent elements, with upper left element zero.at n=15A299609