# A085687 (b-file synthesized from sequence entry)
0 1
1 6
2 36
3 224
4 1440
5 9504
6 64064
7 439296
8 3055104
9 21498880
10 152807424
11 1095450624
12 7911587840
13 57511157760
14 420459724800
15 3089600348160
16 22806128885760
17 169033661153280
18 1257467341701120
19 9385880636620800
20 70271680244613120
21 527595313582571520