| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 25 |
| 4 | 127 |
| 5 | 449 |
| 6 | 2279 |
| 7 | 8057 |
| 8 | 40895 |
| 9 | 144577 |
| 10 | 733831 |
| 11 | 2594329 |
| 12 | 13168063 |
| 13 | 46553345 |
| 14 | 236291303 |
| 15 | 835365881 |
| 16 | 4240075391 |
| 17 | 14990032513 |
| 18 | 76085065735 |
| 19 | 268985219353 |
| 20 | 1365291107839 |
| 21 | 4826743915841 |
| 22 | 24499154875367 |
| 23 | 86612405265785 |
| 24 | 439619496648767 |
| 25 | 1554196550868289 |
[1,7,25,127,449,2279,8057,40895,144577,733831, 2594329,13168063,46553345,236291303,835365881, 4240075391,14990032513,76085065735,268985219353, 1365291107839,4826743915841,24499154875367, 86612405265785,439619496648767,1554196550868289] |