A new class of Hadamard matrices

A Hadamard matrix H is an orthogonal square matrix of order m all the entries of which are either + 1 or - 1; i. e. where H′ denotes the transpose of H and I m is the identity matrix of order m . For such a matrix to exist it is necessary [1] that It has been conjectured, but not yet proved, that this condition is also sufficient. However, many values of m have been found for which a Hadamard matrix of order m can be constructed. The following is a list of such m ( p denotes an odd prime).