# A127231 (b-file synthesized from sequence entry)
0 2
1 3
2 25
3 721
4 40321
5 3628801
6 479001601
7 87178291201
8 20922789888001
9 6402373705728001
10 2432902008176640001
11 1124000727777607680001
12 620448401733239439360001
13 403291461126605635584000001
14 304888344611713860501504000001
15 265252859812191058636308480000001