n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 16 |
3 | 66 |
4 | 280 |
5 | 1218 |
6 | 5422 |
7 | 24666 |
8 | 114540 |
9 | 542278 |
10 | 2614178 |
11 | 12814102 |
12 | 63772982 |
13 | 321754290 |
14 | 1643263134 |
15 | 8483485886 |
16 | 44214343344 |
17 | 232362906298 |
18 | 1230090777342 |
19 | 6553657204178 |
20 | 35113127086114 |
21 | 189062666857686 |
22 | 1022459506515674 |
[1,4,16,66,280,1218,5422,24666,114540,542278, 2614178,12814102,63772982,321754290,1643263134, 8483485886,44214343344,232362906298,1230090777342, 6553657204178,35113127086114,189062666857686, 1022459506515674] |