# A013172 (b-file synthesized from sequence entry)
0 1
1 2
2 4
3 12
4 48
5 232
6 1344
7 8960
8 68096
9 580480
10 5489024
11 57192960
12 649853952
13 8028368896
14 106867367936
15 1530617461760
16 23404867387392
17 381866595811328
18 6602987646386176
19 120993556601405440