# A273698 (b-file synthesized from sequence entry)
0 1
1 4
2 144
3 576
4 518400
5 2073600
6 3657830400
7 696729600
8 13168189440000
9 52672757760000
10 45888506560512000
11 917770131210240000
12 6840049010896797696000000
13 1013340594206932992000000
14 984967057569138868224000000
15 562838318610936496128000000