# A145359 (b-file synthesized from sequence entry)
1 1
2 6
3 78
4 588
5 6804
6 62496
7 753984
8 8273664
9 109118016
10 1408700160
11 20697223680
12 309818234880
13 5100265336320
14 87215844925440
15 1605019401216000
16 30898776106598400
17 631358784683827200
18 13503510009903513600
19 303781522335363072000
20 7137966147222822912000