# A012587 (b-file synthesized from sequence entry)
0 0
1 1
2 2
3 4
4 24
5 180
6 1240
7 10456
8 112896
9 1316816
10 16378528
11 229634304
12 3569726336
13 59315089600
14 1055150016128
15 20254767489152
16 415619313491968
17 9028238025838848
18 207506148418183680
19 5043727679716764672