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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 47 |
| 6 | 200 |
| 7 | 1073 |
| 8 | 6986 |
| 9 | 53219 |
| 10 | 462332 |
| 11 | 4500245 |
| 12 | 48454958 |
| 13 | 571411271 |
| 14 | 7321388384 |
| 15 | 101249656697 |
| 16 | 1502852293010 |
| 17 | 23827244817323 |
| 18 | 401839065437636 |
| 19 | 7182224591785949 |
| 20 | 135607710526966262 |
| 21 | 2696935204638786575 |
[1,2,5,14,47,200,1073,6986,53219,462332,4500245, 48454958,571411271,7321388384,101249656697, 1502852293010,23827244817323,401839065437636, 7182224591785949,135607710526966262, 2696935204638786575] |