# A169308 (b-file synthesized from sequence entry)
0 1
1 7
2 42
3 252
4 1512
5 9072
6 54432
7 326592
8 1959552
9 11757312
10 70543872
11 423263232
12 2539579392
13 15237476352
14 91424858112
15 548549148672
16 3291294892032
17 19747769352192
18 118486616113152
19 710919696678912
20 4265518180073472