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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