n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 1 |
5 | 4 |
6 | 30 |
7 | 220 |
8 | 1855 |
9 | 17304 |
10 | 177996 |
11 | 2002440 |
12 | 24474285 |
13 | 323060540 |
14 | 4581585866 |
15 | 69487385604 |
16 | 1122488536715 |
17 | 19242660629360 |
18 | 348933579412440 |
19 | 6673354706262864 |
20 | 134252194678935321 |
21 | 2834212998777523380 |
22 | 62651024183503148470 |
23 | 1447238658638922729580 |
[0,0,0,1,4,30,220,1855,17304,177996,2002440, 24474285,323060540,4581585866,69487385604, 1122488536715,19242660629360,348933579412440, 6673354706262864,134252194678935321, 2834212998777523380,62651024183503148470, 1447238658638922729580] |