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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 31 |
| 4 | 140 |
| 5 | 571 |
| 6 | 2413 |
| 7 | 10069 |
| 8 | 42205 |
| 9 | 176624 |
| 10 | 739573 |
| 11 | 3096173 |
| 12 | 12962845 |
| 13 | 54270579 |
| 14 | 227212636 |
| 15 | 951259751 |
| 16 | 3982596009 |
| 17 | 16673747193 |
| 18 | 69807202249 |
| 19 | 292258553696 |
| 20 | 1223585260409 |
| 21 | 5122727328297 |
| 22 | 21447083573633 |
| 23 | 89791504401207 |
[1,9,31,140,571,2413,10069,42205,176624,739573, 3096173,12962845,54270579,227212636,951259751, 3982596009,16673747193,69807202249,292258553696, 1223585260409,5122727328297,21447083573633, 89791504401207] |