# A267987 (b-file synthesized from sequence entry) 0 4 1 8 2 48 3 400 4 3920 5 42336 6 487872 7 5889312 8 73616400 9 945561760 10 12412647104 11 165878102208 12 2249987591488 13 30906422960000 14 429157758816000 15 6015361252737600 16 85011208292365200 17 1210159553338375200 18 17338543308064440000 19 249857534618318088000