OFFSET
2,3
COMMENTS
Equally, number of skew digraphs in switching classes of Hadamard matrices of order 4n.
LINKS
J. Gebel, Integer points on Mordell curves [Cached copy, after the original web site tnt.math.se.tmu.ac.jp was shut down in 2017]
Edward Spence, Classification of Hadamard matrices of order 24 and 28, Discrete Math. 140 (1995), no. 1-3, 185-243.
CROSSREFS
KEYWORD
nonn,hard,more,nice
AUTHOR
EXTENSIONS
Better name suggested by Brendan McKay, Oct 31 2007
STATUS
approved