The following is a skew Hadamard matrix of order 4·57 = 228 constructed from a new set of good matrices of order 57 found by MathCheck. Prior to our work, searches had only been run up to order 49. The coloured squares represent one and the white squares represent negative one and each good matrix is highlighted using a different colour. The colour scheme based on the one used in NASA's construction of a Hadamard matrix of order 4·23 = 92 using Williamson matrices of order 23.
