# A068774 (b-file synthesized from sequence entry) 1 0 2 0 3 0 4 8 5 40 6 240 7 1120 8 4480 9 17280 10 65280 11 253440 12 1015808 13 4126720 14 16773120 15 67624960 16 270499840 17 1077903360 18 4294901760 19 17146183680 20 68585259008 21 274608947200 22 1099510579200 23 4400191897600 24 17600767590400 25 70385915658240 26 281474959933440