# A318397 (b-file synthesized from sequence entry) 0 1 1 2 2 1 3 6 4 8 5 1 6 20 7 54 8 18 9 1 10 70 11 320 12 216 13 32 14 1 15 252 16 1750 17 2000 18 600 19 50 20 1 21 924 22 9072 23 15750 24 8000 25 1350 26 72 27 1 28 3432 29 45276 30 111132 31 85750 32 24500 33 2646 34 98 35 1 36 12870 37 219648 38 724416 39 790272 40 343000 41 62720 42 4704 43 128 44 1 45 48620 46 1042470 47 4447872 48 6519744 49 4000752 50 1111320 51 141120 52 7776 53 162 54 1