n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 0 |
4 | 0 |
5 | 0 |
6 | 720 |
7 | 7560 |
8 | 50400 |
9 | 272160 |
10 | 1300320 |
11 | 5738040 |
12 | 23958000 |
13 | 96061680 |
14 | 373477104 |
15 | 1417295880 |
16 | 5274360000 |
17 | 19313985600 |
18 | 69770966976 |
19 | 249130574424 |
20 | 880629138000 |
[0,0,0,0,0,0,720,7560,50400,272160,1300320, 5738040,23958000,96061680,373477104,1417295880, 5274360000,19313985600,69770966976,249130574424, 880629138000] |