825604417domain: NAppears in sequencesExpansion of (1-x)^(-1)/(1+x-2*x^2+x^3).at n=28A077899Number of nX2 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=26A317759