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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 6 |
| 6 | 12 |
| 7 | 28 |
| 8 | 65 |
| 9 | 160 |
| 10 | 408 |
| 11 | 1074 |
| 12 | 2898 |
| 13 | 7998 |
| 14 | 22508 |
| 15 | 64426 |
| 16 | 187251 |
| 17 | 551730 |
| 18 | 1645840 |
| 19 | 4964876 |
| 20 | 15130808 |
| 21 | 46545788 |
| 22 | 144424944 |
| 23 | 451715460 |
[1,1,1,2,3,6,12,28,65,160,408,1074,2898,7998, 22508,64426,187251,551730,1645840,4964876, 15130808,46545788,144424944,451715460] |