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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 2 |
| 6 | 3 |
| 7 | 6 |
| 8 | 10 |
| 9 | 21 |
| 10 | 46 |
| 11 | 106 |
| 12 | 253 |
| 13 | 820 |
| 14 | 2128 |
| 15 | 8527 |
| 16 | 25843 |
| 17 | 122734 |
| 18 | 425169 |
| 19 | 2572337 |
| 20 | 9924088 |
| 21 | 75407076 |
| 22 | 331598798 |
| 23 | 3087553649 |
| 24 | 15467749658 |
| 25 | 179756366268 |
| 26 | 1016119110332 |
| 27 | 14755861942091 |
| 28 | 94597276047265 |
| 29 | 1702584089571489 |
[1,1,1,2,2,3,6,10,21,46,106,253,820,2128,8527, 25843,122734,425169,2572337,9924088,75407076, 331598798,3087553649,15467749658,179756366268, 1016119110332,14755861942091,94597276047265, 1702584089571489] |