# The cocyclic Hadamard matrices of order less than 40

@article{Cathin2011TheCH, title={The cocyclic Hadamard matrices of order less than 40}, author={Padraig {\'O} Cath{\'a}in and Marc R{\"o}der}, journal={Designs, Codes and Cryptography}, year={2011}, volume={58}, pages={73-88} }

In this paper all cocyclic Hadamard matrices of order less than 40 are classified. That is, all such Hadamard matrices are explicitly constructed, up to Hadamard equivalence. This represents a significant extension and completion of work by de Launey and Ito. The theory of cocyclic development is discussed, and an algorithm for determining whether a given Hadamard matrix is cocyclic is described. Since all Hadamard matrices of order at most 28 have been classified, this algorithm suffices to… Expand

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