Calculating the sequences behind a hexagonal lattice based equal circle packing in the Euclidian plane

Abstract: The article presents the mathematical sequences describing circle packing densities in four different geometric configurations involving a hexagonal lattice based equal circle packing in the Euclidian plane. The calculated sequences take form of either polynomials or rational functions. If the circle packing area is limited with a circle, the packing densities tend to decrease with increasing number of the packed circles and converge to values lower than {\pi}/(2\sqrt{3}). In cases with packing areas limited by equilateral triangles or equilateral hexagons the packing densities tend to increase with increasing number of the packed circles and converge to {\pi}/(2\sqrt{3}). The equilateral hexagons are shown to be the preferred equal circle packing surface areas with practical applications searching for high equal circle packing densities, since the packing densities with circle packing inside equilateral hexagons converge faster to {\pi}/(2\sqrt{3}) than in the case of equilateral triangle packing surface areas.