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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 17 |
| 4 | 65 |
| 5 | 1457 |
| 6 | 10657 |
| 7 | 307841 |
| 8 | 3403521 |
| 9 | 121414689 |
| 10 | 1810995009 |
| 11 | 77157569073 |
| 12 | 1453708980033 |
| 13 | 72128854709329 |
| 14 | 1644987113677793 |
| 15 | 93235988902015009 |
| 16 | 2498605538747794433 |
| 17 | 159345372352540823361 |
| 18 | 4909485778021467744897 |
| 19 | 348042700926255242296657 |
[1,1,1,17,65,1457,10657,307841,3403521,121414689, 1810995009,77157569073,1453708980033, 72128854709329,1644987113677793,93235988902015009, 2498605538747794433,159345372352540823361, 4909485778021467744897,348042700926255242296657] |