# A052593 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 6
4 48
5 360
6 2880
7 25200
8 282240
9 3628800
10 50803200
11 758419200
12 12454041600
13 224172748800
14 4358914560000
15 90229531392000
16 1987665039360000
17 46595053080576000
18 1158829640736768000
19 30411275102208000000
20 839351192820940800000
21 24319288473733693440000