1502472domain: NAppears in sequencesNumber of polyhexes with n hexagons, having reflectional symmetry (see Harary and Read for precise definition).at n=22A002215Catafusenes (see reference for precise definition).at n=22A044044Expansion of 1 - 3*x - sqrt(1 - 6*x + 5*x^2).at n=11A122737