A linear array that achieves maximum resolution for a given number of antennas is advantageous in earth-rotation aperture synthesis. Such a minimum redundancy linear array (MRLA) is obtained by reducing redundant spacings present in the array. In the present paper some methods of obtaining optimum MRLA's for a large number of antennas are examined. In one of the methods, a large MRLA is obtained by using small MRLA's recursively as constituent elements for the new array. If use is restricted to only zero-redundancy arrays as small MRLA's, the four-antenna zero-redundancy array is advantageous. Three methods of finding MRLA's for an arbitrary number of antennas with the aid of a digital computer are described.