# A153989 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 5
4 11
5 46
6 267
7 1767
8 17587
9 243760
10 4437947
11 112889388
12 3947281130
13 187476143214
14 12242161648191
15 1095392081180001
16 134002137948473492
17 22462563463091094957
18 5156385913433257078626