n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 20 |
4 | 152 |
5 | 1216 |
6 | 13264 |
7 | 145760 |
8 | 2031872 |
9 | 28617856 |
10 | 480749824 |
11 | 8243878400 |
12 | 162085486592 |
13 | 3262756228096 |
14 | 73483961257984 |
15 | 1695754607421440 |
16 | 42992308610957312 |
17 | 1118097332524711936 |
18 | 31487163119164063744 |
19 | 910421423509984378880 |
20 | 28187970433553669292032 |
21 | 896242635855128514789376 |
[1,1,4,20,152,1216,13264,145760,2031872,28617856, 480749824,8243878400,162085486592,3262756228096, 73483961257984,1695754607421440,42992308610957312, 1118097332524711936,31487163119164063744, 910421423509984378880,28187970433553669292032, 896242635855128514789376] |