[seqfan] Hadamard matrices of small order and Yang conjecture

[Jonathan Post]

191, 5767, 7081, 8249

Actually, several sequences here, and/or corrections tol old seqs?

 arXiv:0912.5091 [ps, pdf, other]
    Title: Hadamard matrices of small order and Yang conjecture
    Authors: Dragomir Z. Djokovic
    Comments: 6 pages, 1 table
    Subjects: Combinatorics (math.CO)

    We show that 138 odd values of n less than 10000 for which one
knows how to construct a Hadamard matrix of order 4n have been
overlooked in the recent handbook of combinatorial designs. There are
four additional odd n, namely 191, 5767, 7081 and 8249, in that range
for which we can construct a Hadamard matrix of order 4n. Our
exhaustive computer searches show that the near-normal sequences NN(n)
exist for n=36,38,40. Thus the Yang conjecture on the existence of
NN(n) for all even n has been verified for n <= 40 but it still
remains open.

Dec 27, 2009