# A191718 (b-file synthesized from sequence entry) 1 1 2 0 3 2 4 2 5 0 6 4 7 0 8 14 9 0 10 10 11 24 12 0 13 70 14 0 15 26 16 0 17 304 18 0 19 340 20 0 21 76 22 720 23 0 24 2548 25 0 26 1540 27 0 28 232 29 0 30 13488 31 0 32 18956 33 0 34 7112 35 0 36 764 37 40320 38 0 39 161936 40 0 41 125580 42 0 43 32424 44 0 45 2620 46 0 47 1011456 48 0 49 1648160 50 0 51 808248 52 0 53 151440 54 0 55 9496 56 3628800