|
%I #11 May 05 2023 09:26:54
%S 1,2,96,328320,440952422400
%N Number of (2n) X (2n) symmetric matrices each of whose rows is a permutation of 1..(2n).
%F a(n) = A035483(n) * (2n)!
%Y Cf. A035481, A036981.
%K more,nonn
%O 0,2
%A _Joshua Zucker_ and Joe Keane
|
