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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 2 |
| 7 | 5 |
| 8 | 13 |
| 9 | 34 |
| 10 | 76 |
| 11 | 286 |
| 12 | 1651 |
| 13 | 10933 |
| 14 | 76130 |
| 15 | 418553 |
| 16 | 3071419 |
| 17 | 37191253 |
| 18 | 597219127 |
| 19 | 11052077737 |
| 20 | 158194282219 |
| 21 | 2500524791374 |
| 22 | 60075261409487 |
| 23 | 2150997470890553 |
| 24 | 103505410541423890 |
| 25 | 3957922747010968084 |
[1,1,1,1,1,1,2,5,13,34,76,286,1651,10933,76130, 418553,3071419,37191253,597219127,11052077737, 158194282219,2500524791374,60075261409487, 2150997470890553,103505410541423890, 3957922747010968084] |