We consider the two-layer row-convex polygons on a rectangular lattice where each polygon can be divided uniquely into two convex polygons. The generating function for the number of such polygons is derived.
Lin, K. Y. (1989). Area-Weighted Moment of Convex Polygons. Chinese Journal of Physics, 27(4), 235-252. https://www.airitilibrary.com/Article/Detail?DocID=05779073-198908-201303150001-201303150001-235-252