# A115508 (b-file synthesized from sequence entry) 1 1 2 2 3 6 4 4 5 4 6 40 7 120 8 72 9 140 10 824 11 3312 12 22320 13 110976 14 1369536 15 9477120 16 3596160 17 3235584 18 36927360 19 286846848 20 700001376 21 3321184800 22 41563274304 23 279121008576 24 3155690872704 25 40885093117440 26 827391601336320 27 11517247876055040 28 76396291822448640 29 822435518222438400