n | a(n) |
---|---|
4 | 1 |
5 | 25 |
6 | 450 |
7 | 7350 |
8 | 117600 |
9 | 1905120 |
10 | 31752000 |
11 | 548856000 |
12 | 9879408000 |
13 | 185513328000 |
14 | 3636061228800 |
15 | 74373979680000 |
16 | 1586644899840000 |
17 | 35272336619520000 |
18 | 816302647480320000 |
19 | 19645683716026368000 |
20 | 491142092900659200000 |
21 | 12740803704070041600000 |
[1,25,450,7350,117600,1905120,31752000,548856000, 9879408000,185513328000,3636061228800, 74373979680000,1586644899840000,35272336619520000, 816302647480320000,19645683716026368000, 491142092900659200000,12740803704070041600000] |