# A012711 (b-file synthesized from sequence entry)
0 0
1 1
2 2
3 6
4 24
5 168
6 1360
7 14280
8 170688
9 2420096
10 38403328
11 687737600
12 13562531840
13 293985622656
14 6920272523008
15 176170136886016
16 4816418604806144
17 140839702493749248
18 4384422821203968000