# A052579 (b-file synthesized from sequence entry)
0 2
1 1
2 2
3 12
4 24
5 120
6 1440
7 5040
8 40320
9 725760
10 3628800
11 39916800
12 958003200
13 6227020800
14 87178291200
15 2615348736000
16 20922789888000
17 355687428096000
18 12804747411456000
19 121645100408832000
20 2432902008176640000