n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 3 |
3 | 18 |
4 | 81 |
5 | 405 |
6 | 1944 |
7 | 9477 |
8 | 45927 |
9 | 223074 |
10 | 1082565 |
11 | 5255361 |
12 | 25509168 |
13 | 123825753 |
14 | 601059771 |
15 | 2917611090 |
16 | 14162371209 |
17 | 68745613437 |
18 | 333698181192 |
19 | 1619805064509 |
20 | 7862698824255 |
21 | 38166342053346 |
22 | 185263315578333 |
[0,1,3,18,81,405,1944,9477,45927,223074,1082565, 5255361,25509168,123825753,601059771,2917611090, 14162371209,68745613437,333698181192, 1619805064509,7862698824255,38166342053346, 185263315578333] |