# A126772 (b-file synthesized from sequence entry)
1 1
2 1
3 1
4 2
5 4
6 12
7 48
8 240
9 1680
10 15120
11 181440
12 2903040
13 60963840
14 1706987520
15 63158538240
16 3094768373760
17 201159944294400
18 17299755209318400
19 1972172093862297600
20 297797986173206937600
21 59559597234641387520000