English

A class of cyclic $(v;k_1,k_2,k_3;\lambda)$ difference families with $v \equiv 3 \pmod{4}$ a prime

Combinatorics 2017-10-12 v2

Abstract

We construct several cyclic (v;k1,k2,k3;λ)(v;k_1,k_2,k_3;\lambda) difference families with v3(mod4)v\equiv3 \pmod{4} a prime and λ=k1+k2+k3(3v1)/4\lambda=k_1+k_2+k_3-(3v-1)/4. Such families can be used in conjunction with the well-known Paley-Todd difference sets to construct skew-Hadamard matrices of order 4v4v. Our main result is that we have constructed for the first time the example of skew-Hadamard matrices of orders 4239=9564\cdot239=956 and 4331=13244\cdot331=1324.

Keywords

Cite

@article{arxiv.1511.08734,
  title  = {A class of cyclic $(v;k_1,k_2,k_3;\lambda)$ difference families with $v \equiv 3 \pmod{4}$ a prime},
  author = {Dragomir Z. Djokovic and Ilias S. Kotsireas},
  journal= {arXiv preprint arXiv:1511.08734},
  year   = {2017}
}

Comments

11 pages, 1 table. Updated version