n | a(n) |
---|---|
1 | 4 |
2 | 16 |
3 | 64 |
4 | 252 |
5 | 992 |
6 | 3900 |
7 | 15328 |
8 | 60228 |
9 | 236624 |
10 | 929580 |
11 | 3651712 |
12 | 14344836 |
13 | 56349296 |
14 | 221349132 |
15 | 869490976 |
16 | 3415475172 |
17 | 13416415184 |
18 | 52701313836 |
19 | 207017071552 |
20 | 813187592388 |
21 | 3194296661552 |
22 | 12547572276300 |
23 | 49288333901920 |
[4,16,64,252,992,3900,15328,60228,236624,929580, 3651712,14344836,56349296,221349132,869490976, 3415475172,13416415184,52701313836,207017071552, 813187592388,3194296661552,12547572276300, 49288333901920] |