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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 21 |
| 3 | 78 |
| 4 | 274 |
| 5 | 927 |
| 6 | 3061 |
| 7 | 9933 |
| 8 | 31824 |
| 9 | 100972 |
| 10 | 317942 |
| 11 | 995088 |
| 12 | 3099105 |
| 13 | 9612735 |
| 14 | 29715525 |
| 15 | 91595391 |
| 16 | 281643480 |
| 17 | 864189486 |
| 18 | 2646805668 |
| 19 | 8093543439 |
| 20 | 24713953515 |
| 21 | 75370741506 |
| 22 | 229604257846 |
| 23 | 698754428388 |
| 24 | 2124616182139 |
[1,5,21,78,274,927,3061,9933,31824,100972,317942, 995088,3099105,9612735,29715525,91595391, 281643480,864189486,2646805668,8093543439, 24713953515,75370741506,229604257846,698754428388, 2124616182139] |