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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 8 |
| 7 | 16 |
| 8 | 43 |
| 9 | 106 |
| 10 | 280 |
| 11 | 721 |
| 12 | 21316 |
| 13 | 109280 |
| 14 | 429033 |
| 15 | 2233210 |
| 16 | 8775424 |
| 17 | 4085769598 |
| 18 | 34540431364 |
| 19 | 292365761174 |
| 20 | 1857930879920 |
| 21 | 14355615174465090 |
| 22 | 98433733136538817 |
| 23 | 1349004838730110732 |
| 24 | 18490450644358531784 |
| 25 | 221781946674143587555 |
| 26 | 26361819178249287412512739 |
[1,1,2,3,5,8,16,43,106,280,721,21316,109280, 429033,2233210,8775424,4085769598,34540431364, 292365761174,1857930879920,14355615174465090, 98433733136538817,1349004838730110732, 18490450644358531784,221781946674143587555, 26361819178249287412512739] |