%I A036980
%S A036980 1,2,96,328320,440952422400
%N A036980 (2n)x(2n) symmetric matrices each of whose rows is a permutation of 1..(2n).
%Y A036980 Cf. A035481, A036981.
%Y A036980 Sequence in context: A064069 A065128 A122222 this_sequence A168442 A091810 
               A165642
%Y A036980 Adjacent sequences: A036977 A036978 A036979 this_sequence A036981 A036982 
               A036983
%K A036980 more,nonn
%O A036980 0,2
%A A036980 Joshua Zucker and Joe Keane (joshua.zucker(AT)stanfordalumni.org)