# A200978 (b-file synthesized from sequence entry)
3 6
4 72
5 720
6 7200
7 75600
8 846720
9 10160640
10 130636800
11 1796256000
12 26345088000
13 410983372800
14 6799906713600
15 118998367488000
16 2196892938240000
17 42682491371520000
18 870722823979008000
19 18611700362551296000
20 416026243398205440000