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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 55 |
| 5 | 183 |
| 6 | 797 |
| 7 | 2857 |
| 8 | 12825 |
| 9 | 48217 |
| 10 | 220507 |
| 11 | 854979 |
| 12 | 3952923 |
| 13 | 15705777 |
| 14 | 73027971 |
| 15 | 295763237 |
| 16 | 1381032123 |
| 17 | 5676154103 |
| 18 | 26604487189 |
| 19 | 110624463481 |
| 20 | 520256180685 |
| 21 | 2183982552123 |
| 22 | 10299802822029 |
| 23 | 43589430230891 |
| 24 | 206028701021297 |
| 25 | 878062403228533 |
| 26 | 4157818861743501 |
| 27 | 17828220266161589 |
[1,1,5,13,55,183,797,2857,12825,48217,220507, 854979,3952923,15705777,73027971,295763237, 1381032123,5676154103,26604487189,110624463481, 520256180685,2183982552123,10299802822029, 43589430230891,206028701021297,878062403228533, 4157818861743501,17828220266161589] |