79243domain: NAppears in sequencesG.f.: ( 1 - x^2 - sqrt( 1 - 2*x^2 - 4*x^3 - 3*x^4 ) ) / ( 2*x^3 ).at n=20A050253Number of n X 2 0..1 arrays with every element equal to 0, 1, 3 or 4 king-move adjacent elements, with upper left element zero.at n=12A297901