n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 4 |
4 | 14 |
5 | 44 |
6 | 135 |
7 | 408 |
8 | 1228 |
9 | 3688 |
10 | 11069 |
11 | 33212 |
12 | 99642 |
13 | 298932 |
14 | 896803 |
15 | 2690416 |
16 | 8071256 |
17 | 24213776 |
18 | 72641337 |
19 | 217924020 |
20 | 653772070 |
21 | 1961316220 |
22 | 5883948671 |
23 | 17651846024 |
24 | 52955538084 |
25 | 158866614264 |
26 | 476599842805 |
[0,0,1,4,14,44,135,408,1228,3688,11069,33212, 99642,298932,896803,2690416,8071256,24213776, 72641337,217924020,653772070,1961316220, 5883948671,17651846024,52955538084,158866614264, 476599842805] |