# A002702 (b-file synthesized from sequence entry)
2 1
3 4
4 120
5 3024
6 151200
7 79200
8 1513512000
9 1513512000
10 51459408000
11 74662922880
12 18068427336960
13 133196739984000
14 1215553449093984000
15 173650492727712000
16 3357242859402432000
17 101013513093196704000
18 2043503369875369321920000