| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 175 |
| 4 | 833 |
| 5 | 3647 |
| 6 | 16513 |
| 7 | 73983 |
| 8 | 332801 |
| 9 | 1495039 |
| 10 | 6719489 |
| 11 | 30195711 |
| 12 | 135700481 |
| 13 | 609828863 |
| 14 | 2740551681 |
| 15 | 12315918335 |
| 16 | 55347249153 |
| 17 | 248728256511 |
| 18 | 1117774675969 |
| 19 | 5023233736703 |
| 20 | 22574207598593 |
| 21 | 101447567933439 |
| 22 | 455901232234497 |
[7,49,175,833,3647,16513,73983,332801,1495039, 6719489,30195711,135700481,609828863,2740551681, 12315918335,55347249153,248728256511, 1117774675969,5023233736703,22574207598593, 101447567933439,455901232234497] |