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| n | a(n) |
|---|---|
| 1 | 23 |
| 2 | 128 |
| 3 | 578 |
| 4 | 2329 |
| 5 | 8898 |
| 6 | 32279 |
| 7 | 111609 |
| 8 | 367415 |
| 9 | 1156446 |
| 10 | 3507097 |
| 11 | 10298283 |
| 12 | 29408921 |
| 13 | 81999117 |
| 14 | 223720287 |
| 15 | 598317070 |
| 16 | 1572579642 |
| 17 | 4069639443 |
| 18 | 10383180004 |
| 19 | 26154898488 |
| 20 | 65117553622 |
[23,128,578,2329,8898,32279,111609,367415,1156446, 3507097,10298283,29408921,81999117,223720287, 598317070,1572579642,4069639443,10383180004, 26154898488,65117553622] |