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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 5 |
| 2 | 17 |
| 3 | 59 |
| 4 | 223 |
| 5 | 757 |
| 6 | 2633 |
| 7 | 8969 |
| 8 | 30431 |
| 9 | 102191 |
| 10 | 341357 |
| 11 | 1134043 |
| 12 | 3749633 |
| 13 | 12351797 |
| 14 | 40558519 |
| 15 | 132820211 |
| 16 | 433927019 |
| 17 | 1414734187 |
| 18 | 4604123551 |
| 19 | 14959716349 |
| 20 | 48537631577 |
| 21 | 157280263711 |
| 22 | 509055969293 |
| 23 | 1645881130301 |
| 24 | 5316347779363 |
| 25 | 17157165731437 |
| 26 | 55325548493311 |
| 27 | 178271206357499 |
[2,5,17,59,223,757,2633,8969,30431,102191,341357, 1134043,3749633,12351797,40558519,132820211, 433927019,1414734187,4604123551,14959716349, 48537631577,157280263711,509055969293, 1645881130301,5316347779363,17157165731437, 55325548493311,178271206357499] |