n | a(n) |
---|---|
0 | 1 |
1 | 20 |
2 | 240 |
3 | 2240 |
4 | 17920 |
5 | 129024 |
6 | 860160 |
7 | 5406720 |
8 | 32440320 |
9 | 187432960 |
10 | 1049624576 |
11 | 5725224960 |
12 | 30534533120 |
13 | 159719096320 |
14 | 821412495360 |
15 | 4161823309824 |
16 | 20809116549120 |
17 | 102821517066240 |
18 | 502682972323840 |
19 | 2434043865989120 |
20 | 11683410556747776 |
21 | 55635288365465600 |
[1,20,240,2240,17920,129024,860160,5406720, 32440320,187432960,1049624576,5725224960, 30534533120,159719096320,821412495360, 4161823309824,20809116549120,102821517066240, 502682972323840,2434043865989120, 11683410556747776,55635288365465600] |