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A036981
Number of (2n+1) X (2n+1) symmetric matrices each of whose rows is a permutation of 1..(2n+1).
6
1, 6, 720, 31449600, 444733651353600, 10070314878246926155776000, 614972203951464612786852376432607232000
OFFSET
0,2
COMMENTS
Number of different schedules for 2n+2 teams. - Andres Cardemil (andrescarde(AT)yahoo.com), Nov 28, 2001
FORMULA
a(n) = A000438(n+1) * (2*n+1)!.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Joshua Zucker and Joe Keane
EXTENSIONS
Two more terms computed from A000438 by Max Alekseyev, Jun 17 2011
STATUS
approved