# A221096 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 42
4 768
5 19460
6 637200
7 25724916
8 1233957312
9 68591031120
10 4338982958400
11 307907317681920
12 24229505587541760
13 2094548798610726432
14 197370092438311892736
15 20140182770328963216000
16 2213078753956025271214080
17 260601290312643875434817280