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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 9 |
| 5 | 24 |
| 6 | 55 |
| 7 | 169 |
| 8 | 454 |
| 9 | 1567 |
| 10 | 4823 |
| 11 | 18422 |
| 12 | 63609 |
| 13 | 265929 |
| 14 | 1014266 |
| 15 | 4595861 |
| 16 | 19143089 |
| 17 | 93286964 |
| 18 | 420483103 |
| 19 | 2189786125 |
| 20 | 10601936382 |
| 21 | 58688597511 |
| 22 | 303349005967 |
| 23 | 1776842374930 |
| 24 | 9754696729753 |
| 25 | 60223101819493 |
| 26 | 349624680839546 |
| 27 | 2267363687696309 |
[0,1,2,5,9,24,55,169,454,1567,4823,18422,63609, 265929,1014266,4595861,19143089,93286964, 420483103,2189786125,10601936382,58688597511, 303349005967,1776842374930,9754696729753, 60223101819493,349624680839546,2267363687696309] |