# A073315 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 2 5 9 6 6 7 6 8 44 9 72 10 24 11 24 12 250 13 700 14 600 15 120 16 120 17 1644 18 6750 19 10200 20 5400 21 720 22 720 23 12348 24 68208 25 154350 26 147000 27 52920 28 5040 29 5040 30 104544 31 735392 32 2274384 33 3292800 34 2163840 35 564480 36 40320 37 40320 38 986256 39 8504928 40 33911136