The coherent propagation and amplification of high-power laser beams in a multicore fiber (MCF) of and lattices of weakly coupled cores is studied. Exact stable analytical nonlinear solutions are found in the form of the out-of-phase distribution that describe the coherent propagation of wave beams in such MCFs. The use of these distributions makes it possible to operate with laser radiation with a power of up to 2N times of the critical self-focusing power in homogeneous media. The analytical results are confirmed by the direct numerical simulation of the wave equation. The limitations on active fiber parameters for stable amplification of the found out-of-phase solution are determined.