# A004308 (b-file synthesized from sequence entry)
4 0
5 0
6 24
7 154
8 1664
9 15984
10 173000
11 2004486
12 25086336
13 337215372
14 4852472744
15 74473953570
16 1214929163904
17 21000334935308
18 383498204201496
19 7379028867234934
20 149233618755354240
21 3165087929247599208
22 70251457394397108280