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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 73 |
| 6 | 237 |
| 7 | 711 |
| 8 | 1988 |
| 9 | 5253 |
| 10 | 13301 |
| 11 | 32673 |
| 12 | 78669 |
| 13 | 187230 |
| 14 | 443398 |
| 15 | 1050209 |
| 16 | 2497187 |
| 17 | 5976456 |
| 18 | 14419577 |
| 19 | 35101838 |
| 20 | 86229874 |
| 21 | 213707024 |
| 22 | 534022585 |
| 23 | 1344450284 |
| 24 | 3407215499 |
| 25 | 8684458421 |
| 26 | 22243751970 |
| 27 | 57208235104 |
| 28 | 147636483121 |
| 29 | 382077767531 |
| 30 | 991081141309 |
| 31 | 2575597009441 |
[1,1,2,6,21,73,237,711,1988,5253,13301,32673, 78669,187230,443398,1050209,2497187,5976456, 14419577,35101838,86229874,213707024,534022585, 1344450284,3407215499,8684458421,22243751970, 57208235104,147636483121,382077767531, 991081141309,2575597009441] |