# A052577 (b-file synthesized from sequence entry)
0 1
1 4
2 26
3 240
4 2904
5 43680
6 786960
7 16531200
8 396789120
9 10713669120
10 321413702400
11 10606692096000
12 381841394457600
13 14891820610867200
14 625456552834713600
15 28145546185236480000
16 1350986237814140928000
17 68900298484208615424000
18 3720616124549638938624000