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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 43 |
| 6 | 145 |
| 7 | 538 |
| 8 | 2194 |
| 9 | 9790 |
| 10 | 47491 |
| 11 | 248706 |
| 12 | 1396799 |
| 13 | 8363711 |
| 14 | 53121000 |
| 15 | 356309314 |
| 16 | 2514395528 |
| 17 | 18606000547 |
| 18 | 143956459002 |
| 19 | 1161612656187 |
| 20 | 9753494344997 |
| 21 | 85044912003502 |
| 22 | 768659919235828 |
| 23 | 7189553986402426 |
| 24 | 69486510911410279 |
| 25 | 693003419860404514 |
[1,1,2,5,14,43,145,538,2194,9790,47491,248706, 1396799,8363711,53121000,356309314,2514395528, 18606000547,143956459002,1161612656187, 9753494344997,85044912003502,768659919235828, 7189553986402426,69486510911410279, 693003419860404514] |