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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 47 |
| 6 | 153 |
| 7 | 515 |
| 8 | 1781 |
| 9 | 6290 |
| 10 | 22593 |
| 11 | 82141 |
| 12 | 301643 |
| 13 | 1117894 |
| 14 | 4173685 |
| 15 | 15679942 |
| 16 | 59231389 |
| 17 | 224775911 |
| 18 | 856426691 |
| 19 | 3274980603 |
| 20 | 12562759119 |
| 21 | 48323739885 |
| 22 | 186348608027 |
| 23 | 720198605807 |
| 24 | 2788959419659 |
| 25 | 10819918605211 |
| 26 | 42044943533093 |
| 27 | 163623798367005 |
| 28 | 637635663128808 |
| 29 | 2487921395396235 |
[1,1,2,5,15,47,153,515,1781,6290,22593,82141, 301643,1117894,4173685,15679942,59231389, 224775911,856426691,3274980603,12562759119, 48323739885,186348608027,720198605807, 2788959419659,10819918605211,42044943533093, 163623798367005,637635663128808,2487921395396235] |