OFFSET
1,1
LINKS
Gilbert, E. N., Latin squares which contain no repeated digrams, SIAM Rev. 7 1965 189--198. MR0179095 (31 #3346).
FORMULA
a(n) = (2*n)!*A141599(n)^2/phi(n).
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Mar 15 2014
STATUS
approved