# A004309 (b-file synthesized from sequence entry)
4 0
5 10
6 60
7 595
8 4512
9 44802
10 457040
11 5159517
12 62939040
13 829049884
14 11727029860
15 177384144795
16 2857827179200
17 48865616001564
18 883930234491000
19 16866107046572417
20 338568863790331200
21 7132984247370166710
22 157374949769998613708