# A151357 (b-file synthesized from sequence entry) 0 1 1 0 2 1 3 3 4 4 5 20 6 65 7 175 8 742 9 2604 10 9072 11 36960 12 139392 13 538824 14 2198625 15 8735727 16 35456850 17 146812952 18 604215326 19 2521642266 20 10617725768 21 44760668160 22 190357768328 23 813800295880 24 3490232753680 25 15055389124320 26 65193213272800 27 283254330047520 28 1235731377864960 29 5407996483238160