# A013180 (b-file synthesized from sequence entry)
0 1
1 4
2 80
3 4480
4 462080
5 77248000
6 18902835200
7 6385348403200
8 2843287396352000
9 1614575957622784000
10 1138477316012441600000
11 976037590707833405440000
12 999765439694232249958400000