# A245373 (b-file synthesized from sequence entry)
0 1
1 2
2 6
3 20
4 80
5 368
6 1904
7 10880
8 67904
9 459008
10 3336704
11 25925120
12 214175744
13 1873092608
14 17276401664
15 167504076800
16 1702214549504
17 18084149854208
18 200388963958784
19 2311212530401280
20 27693720143396864
21 344157474490155008
22 4428851361694613504
23 58933575269230837760