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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 11 |
| 3 | 63 |
| 4 | 388 |
| 5 | 2484 |
| 6 | 16330 |
| 7 | 109549 |
| 8 | 745851 |
| 9 | 5141513 |
| 10 | 35807609 |
| 11 | 251514544 |
| 12 | 1779289072 |
| 13 | 12663046683 |
| 14 | 90583092779 |
| 15 | 650818310772 |
| 16 | 4693790254019 |
| 17 | 33965214382094 |
| 18 | 246504409256254 |
| 19 | 1793728983702287 |
| 20 | 13083256171763427 |
[1,2,11,63,388,2484,16330,109549,745851,5141513, 35807609,251514544,1779289072,12663046683, 90583092779,650818310772,4693790254019, 33965214382094,246504409256254,1793728983702287, 13083256171763427] |