n | a(n) |
---|---|
1 | 0 |
2 | 2 |
3 | 6 |
4 | 28 |
5 | 140 |
6 | 740 |
7 | 4056 |
8 | 22904 |
9 | 132344 |
10 | 778832 |
11 | 4652404 |
12 | 28140536 |
13 | 172021360 |
14 | 1061153560 |
15 | 6597813620 |
16 | 41307119692 |
17 | 260198053200 |
18 | 1647958588568 |
19 | 10488324116052 |
20 | 67046234983840 |
21 | 430300354820176 |
22 | 2771678138269600 |
23 | 17912347088664868 |
24 | 116113406138798112 |
[0,2,6,28,140,740,4056,22904,132344,778832, 4652404,28140536,172021360,1061153560,6597813620, 41307119692,260198053200,1647958588568, 10488324116052,67046234983840,430300354820176, 2771678138269600,17912347088664868, 116113406138798112] |