# A052572 (b-file synthesized from sequence entry)
0 1
1 4
2 10
3 36
4 168
5 960
6 6480
7 50400
8 443520
9 4354560
10 47174400
11 558835200
12 7185024000
13 99632332800
14 1482030950400
15 23538138624000
16 397533007872000
17 7113748561920000
18 134449847820288000
19 2676192208994304000