# A122417 (b-file synthesized from sequence entry)
1 2
2 6
3 24
4 120
5 720
6 24
7 40320
8 120
9 5040
10 720
11 479001600
12 120
13 87178291200
14 40320
15 720
16 5040
17 6402373705728000
18 5040
19 2432902008176640000
20 720
21 40320
22 479001600
23 620448401733239439360000
24 120
25 39916800
26 87178291200
27 3628800
28 40320