n | a(n) |
---|---|
1 | 1 |
2 | 7 |
3 | 31 |
4 | 172 |
5 | 903 |
6 | 4859 |
7 | 26123 |
8 | 141519 |
9 | 769915 |
10 | 4209720 |
11 | 23118268 |
12 | 127495912 |
13 | 705885128 |
14 | 3922515554 |
15 | 21871461990 |
16 | 122341995397 |
17 | 686381562245 |
18 | 3861568338064 |
19 | 21781724157952 |
20 | 123162942539680 |
21 | 698010289536681 |
[1,7,31,172,903,4859,26123,141519,769915,4209720, 23118268,127495912,705885128,3922515554, 21871461990,122341995397,686381562245, 3861568338064,21781724157952,123162942539680, 698010289536681] |