# A003425 (b-file synthesized from sequence entry) 0 1 1 1 2 6 3 114 4 5256 5 507720 6 93616560 7 30894489360 8 17407086641280 9 16152167106391680 10 23990233574783750400 11 55735096448700749203200 12 198720975339675515386598400 13 1070118060127292955589511500800 14 8585695098723146508385537345689600 15 101432601341702692223559539854263552000