1383887domain: NAppears in sequencesExpansion of e.g.f.: tan(sin(arctan(x))) (odd powers only).at n=5A012021Number of 3Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4.at n=8A240414