n | a(n) |
---|---|
0 | 2 |
1 | 4 |
2 | 12 |
3 | 40 |
4 | 136 |
5 | 464 |
6 | 1584 |
7 | 5408 |
8 | 18464 |
9 | 63040 |
10 | 215232 |
11 | 734848 |
12 | 2508928 |
13 | 8566016 |
14 | 29246208 |
15 | 99852800 |
16 | 340918784 |
17 | 1163969536 |
18 | 3974040576 |
19 | 13568223232 |
20 | 46324811776 |
21 | 158162800640 |
22 | 540001579008 |
23 | 1843680714752 |
24 | 6294719700992 |
[2,4,12,40,136,464,1584,5408,18464,63040,215232, 734848,2508928,8566016,29246208,99852800, 340918784,1163969536,3974040576,13568223232, 46324811776,158162800640,540001579008, 1843680714752,6294719700992] |