Consider the standard field equations relating spacetime curvature, the cosmological term, and the matter source. The present paper examines the consequences of the boundary relation Lambda R_H^2 = pi^3 / 15, together with an independent horizon state count N, where R_H is the horizon radius. The coefficient pi^3 / 15 is obtained from the Stefan-Boltzmann law on a spherical radiating surface in dimensionless form. Under these assumptions, both the cosmological term and the gravitational coupling may be expressed in terms of the horizon variables R_H and N. In particular, Lambda = pi^3 / (15 R_H^2), G = 4 pi c^3 R_H^2 / (hbar N), and the coupling coefficient 8 pi G / c^4 = 32 pi^2 R_H^2 / (hbar c N). The field equations therefore admit a form in which the constants G and Lambda are replaced by boundary quantities associated with the horizon radius and its state count. The result is algebraic and conditional. It is based on the adopted boundary relation and on the independent specification of N, and no microscopic derivation is assumed.