# A058645 (b-file synthesized from sequence entry) 0 0 1 1 2 10 3 54 4 224 5 800 6 2592 7 7840 8 22528 9 62208 10 166400 11 433664 12 1105920 13 2768896 14 6823936 15 16588800 16 39845888 17 94699520 18 222953472 19 520486912 20 1205862400 21 2774532096 22 6343884800 23 14422114304 24 32614907904 25 73400320000