English

Skew-Hadamard matrices of orders 188 and 388 exist

Combinatorics 2009-03-18 v2

Abstract

We construct several difference families on cyclic groups of orders 47 and 97, and use them to construct skew-Hadamard matrices of orders 188 and 388. Such difference families and matrices are constructed here for the first time. The matrices are constructed by using the Goethals-Seidel array.

Keywords

Cite

@article{arxiv.0704.0640,
  title  = {Skew-Hadamard matrices of orders 188 and 388 exist},
  author = {Dragomir Z. Djokovic},
  journal= {arXiv preprint arXiv:0704.0640},
  year   = {2009}
}

Comments

7 pages, no figures, a paragraph added to the introduction, two misprints corrected. To appear in the International Mathematical Forum