n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 18 |
4 | 89 |
5 | 466 |
6 | 2537 |
7 | 14209 |
8 | 81316 |
9 | 473338 |
10 | 2793454 |
11 | 16674417 |
12 | 100487896 |
13 | 610549829 |
14 | 3735850007 |
15 | 23000055178 |
16 | 142370597601 |
17 | 885521350882 |
18 | 5531501612071 |
19 | 34686798239678 |
20 | 218273864005214 |
21 | 1377897874711437 |
[1,4,18,89,466,2537,14209,81316,473338,2793454, 16674417,100487896,610549829,3735850007, 23000055178,142370597601,885521350882, 5531501612071,34686798239678,218273864005214, 1377897874711437] |