n | a(n) |
---|---|
2 | 1 |
3 | 8 |
4 | 58 |
5 | 272 |
6 | 1770 |
7 | 7428 |
8 | 46928 |
9 | 189808 |
10 | 1185645 |
11 | 4724160 |
12 | 29362806 |
13 | 116207424 |
14 | 720606705 |
15 | 2842936320 |
16 | 17610412600 |
17 | 69378730880 |
18 | 429579843435 |
19 | 1691519468760 |
20 | 10472653252550 |
21 | 41235710124400 |
22 | 255326054688320 |
23 | 1005560117623204 |
24 | 6227515552731528 |
25 | 24534901740913872 |
[1,8,58,272,1770,7428,46928,189808,1185645, 4724160,29362806,116207424,720606705,2842936320, 17610412600,69378730880,429579843435, 1691519468760,10472653252550,41235710124400, 255326054688320,1005560117623204,6227515552731528, 24534901740913872] |