# A305923 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 21 4 105 5 580 6 4332 7 33173 8 333057 9 3249334 10 41175698 11 485901669 12 7470988137 13 102962077608 14 1870375878472 15 29342124588357 16 617978798588225 17 10818920340476010 18 260570216908845406 19 5009431835664474101 20 136578252867673635369 21 2844357524328057280332 22 87134882338620095240484