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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 21 |
| 3 | 271 |
| 4 | 5065 |
| 5 | 122811 |
| 6 | 3651997 |
| 7 | 128566663 |
| 8 | 5227782161 |
| 9 | 241072839667 |
| 10 | 12430169195941 |
| 11 | 708612945554559 |
| 12 | 44253858433505497 |
| 13 | 3004570398043291819 |
| 14 | 220341964157226260525 |
| 15 | 17357760973540312138231 |
| 16 | 1461813975265547356467745 |
| 17 | 131061164660246579394042339 |
[1,3,21,271,5065,122811,3651997,128566663, 5227782161,241072839667,12430169195941, 708612945554559,44253858433505497, 3004570398043291819,220341964157226260525, 17357760973540312138231,1461813975265547356467745, 131061164660246579394042339] |