# A008380 (b-file synthesized from sequence entry)
1 6
2 50
3 1176
4 54792
5 4251456
6 495480960
7 80990184960
8 17683570598400
9 4972664013004800
10 1750589607352320000
11 754268505333719040000
12 390464536066453094400000
13 239146855253471119933440000