# A073773 (b-file synthesized from sequence entry) 0 0 1 0 2 0 3 6 4 40 5 152 6 480 7 1376 8 3712 9 9600 10 24064 11 58880 12 141312 13 333824 14 778240 15 1794048 16 4096000 17 9273344 18 20840448 19 46530560 20 103284736 21 228065280 22 501219328 23 1096810496 24 2390753280 25 5192548352 26 11240734720 27 24259854336