n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 18 |
4 | 224 |
5 | 1320 |
6 | 42552 |
7 | 262864 |
8 | 12232320 |
9 | 169594560 |
10 | 6117023600 |
11 | 61920993024 |
12 | 8022787347456 |
13 | 56694391376896 |
14 | 5193025319432160 |
15 | 174746314698336000 |
16 | 10338252997184749568 |
17 | 121439552019384139776 |
18 | 26096843176349347142208 |
19 | 262144006402373705728000 |
[1,1,4,18,224,1320,42552,262864,12232320, 169594560,6117023600,61920993024,8022787347456, 56694391376896,5193025319432160, 174746314698336000,10338252997184749568, 121439552019384139776,26096843176349347142208, 262144006402373705728000] |