1664050domain: NAppears in sequencesG.f.: x*(1 - x + x^2)/((1-x)^2 * (1 - x - x^2)).at n=28A104161Number of n X 2 0..1 arrays with exactly n+2-2 having value 1 and no three 1s forming an isosceles right triangle.at n=26A272952