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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 52 |
| 5 | 200 |
| 6 | 824 |
| 7 | 3549 |
| 8 | 15745 |
| 9 | 71343 |
| 10 | 328537 |
| 11 | 1532838 |
| 12 | 7230341 |
| 13 | 34425026 |
| 14 | 165230211 |
| 15 | 798643501 |
| 16 | 3884110353 |
| 17 | 18993027790 |
| 18 | 93325418867 |
| 19 | 460562269745 |
| 20 | 2281769792691 |
| 21 | 11344607718373 |
| 22 | 56585135577335 |
| 23 | 283067227288767 |
| 24 | 1419859530338142 |
| 25 | 7139644680794750 |
[1,2,5,15,52,200,824,3549,15745,71343,328537, 1532838,7230341,34425026,165230211,798643501, 3884110353,18993027790,93325418867,460562269745, 2281769792691,11344607718373,56585135577335, 283067227288767,1419859530338142,7139644680794750] |