# A073972 (b-file synthesized from sequence entry)
1 0
2 0
3 0
4 36
5 300
6 1440
7 7056
8 42336
9 272160
10 1700352
11 10349856
12 62099136
13 367960320
14 2173796352
15 12940881408
16 77716392192
17 468419708160
18 2821539889152
19 16960580969472
20 101763485816832
21 609985806796800
22 3656220357427200
23 21926115464435712
24 131556692786614272