# A264702 (b-file synthesized from sequence entry) 1 1 2 3 3 6 4 36 5 288 6 2240 7 20736 8 264384 9 2892672 10 63452160 11 1528823808 12 36691771392 13 941182156800 14 29143203840000 15 803229696000000 16 36978425856000000