# A217213 (b-file synthesized from sequence entry)
0 0
1 0
2 0
3 4
4 30
5 168
6 840
7 3960
8 18018
9 80080
10 350064
11 1511640
12 6466460
13 27457584
14 115892400
15 486748080
16 2035917450
17 8485840800
18 35263382880
19 146157442200
20 604404010980
21 2494365759600
22 10275832148400
23 42264944401680
24 173588164506900
25 712027089322848
26 2917167840871200
27 11938779496898800