Data are presented for the coherent production of 37 and 57 final states at 15.1 GeV/c on 8 target nuclei ranging from Be to Pb. Approximately 3000 coherent events were collected for each target. The differential cross-sections exhibit the sharp forward peak characteristic of coherent production. The 3π invariant mass-spectrum for coherent events does not show a sharp A₁ resonance, but presents a broad low mass enhancement. As expected the A₂ meson appears only in the sample of incoherent events. An optical model including absorption is well able to describe the differential cross-sections, yielding nuclear radii in good agreement with the strong interaction radii measured in another experiment. The optical model has been used to extract the total cross-sections of the 3π and 5π systems from the A--dependence of the coherent production cross-section. These total cross-sections are found to be independent of the mass of the produced system and always compatible with the single pion total cross-section. An interpretation of this result is presented.