# A084709 (b-file synthesized from sequence entry)
1 4
2 12
3 60
4 180
5 1620
6 9720
7 417960
8 7523280
9 308454480
10 25293267360
11 1593475843680
12 74893364652960
13 4793175337789440
14 517662936481259520
15 21224180395731640320
16 4075042635980474941440
17 611256395397071241216000