# A229036 (b-file synthesized from sequence entry)
0 1
1 2
2 21
3 270
4 4212
5 77760
6 1662120
7 40415760
8 1102248000
9 33331979520
10 1107097891200
11 40069801094400
12 1569793384051200
13 66185883219456000
14 2988292627358438400
15 143855017177487616000
16 7355369573944584192000
17 398090614491857903616000
18 22737098558477268725760000