# A128811 (b-file synthesized from sequence entry) 1 1 2 4 3 35 4 240 5 3003 6 26880 7 415701 8 4435200 9 79676025 10 968647680 11 19535112675 12 263472168960 13 5837993287875 14 85816649318400 15 2058476433304725 16 32567418416332800 17 836589039864843825 18 14112547980410880000