Some new symmetric Hadamard matrices
Combinatorics
2024-04-23 v2
Abstract
First examples of symmetric Hadamard matrices of orders 508 and 764 are constructed. The method used is known as the propus construction. A conjecture regarding this method is formally proposed but it appears implicitly in three previous joint papers with N. A. Balonin et alias. The conjecture has been verified for Hadamard matrices of order 4v with odd v<54. In this note the conjecture is verified for v=55,57,59,61,63.
Keywords
Cite
@article{arxiv.2101.05429,
title = {Some new symmetric Hadamard matrices},
author = {Dragomir Ž. Đoković},
journal= {arXiv preprint arXiv:2101.05429},
year = {2024}
}
Comments
14 pages. In the second version, Conjecture 1 is fully verified also in the case v=63