OFFSET
1,11
COMMENTS
The number of inequivalent maximal determinant {-1,1} matrices of order n where two matrices are considered equivalent if one can be obtained from the other by permuting rows, permuting columns and multiplying rows or columns by -1. Additional terms: a(24)=60, a(25)=78, a(28)=487. The terms a(4n) are given in sequence A007299.
LINKS
R. P. Brent, W. P. Orrick, J. Osborn, and P. Zimmermann, Maximal determinants and saturated D-optimal designs of orders 19 and 37, arXiv:1112.4160 [math.CO], 2011.
J. H. E. Cohn, On the number of D-optimal designs, J. Combin. Theory Ser. A 66 (1994) 214-225.
W. P. Orrick, On the enumeration of some D-optimal designs, arXiv:math/0511141 [math.CO], 2005-2006.
W. P. Orrick and B. Solomon, The Hadamard maximal determinant problem
Warren D. Smith, Studies in Computational Geometry Motivated by Mesh Generation, Ph. D. dissertation, Princeton University (1988).
E. Spence, Ted Spence's home page, website.
J. Williamson, Determinants whose elements are 0 and 1, Amer. Math. Monthly 53 (1946), 427-434. Math. Rev. 8,128g.
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
William P. Orrick, Nov 08 2005
EXTENSIONS
Added a(19)-a(21) and Brent et al. reference.
Edited by William P. Orrick, Dec 20 2011
STATUS
approved