# A024217 (b-file synthesized from sequence entry)
1 1
2 3
3 25
4 222
5 3166
6 47016
7 951544
8 19827408
9 520029520
10 13952218560
11 449559799360
12 14756761434240
13 563961412362880
14 21893890640563200
15 968019931702297600
16 43385863589508249600
17 2178487766250586470400
18 110704921777161066700800
19 6222745685273069016064000