OFFSET
1,2
COMMENTS
Let p = (p1..pn) and q = (q1..qn) be two random permutations of (1..n); call the pair (p,q) balanced if the number of i with pi > qi is the same as the number of i with pi < qi. Then a(n) is the number of balanced pairs.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jan Lakota, Oct 04 2011
EXTENSIONS
a(1)-a(6) computed by Jan Lakota; extended by N. J. A. Sloane, Oct 04 2011
STATUS
approved