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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 35 |
| 4 | 969 |
| 5 | 302621 |
| 6 | 437989 |
| 7 | 657359 |
| 8 | 939929 |
| 9 | 3737581 |
| 10 | 6435689 |
| 11 | 9290431 |
| 12 | 21084251 |
| 13 | 26536591 |
| 14 | 39338069 |
| 15 | 44101441 |
| 16 | 61690919 |
| 17 | 112805879 |
| 18 | 289442201 |
| 19 | 439918931 |
| 20 | 1008077071 |
| 21 | 1103914379 |
| 22 | 1220664491 |
| 23 | 1369657969 |
| 24 | 1504148881 |
| 25 | 1779510701 |
| 26 | 1868223839 |
| 27 | 2252547431 |
[1,4,35,969,302621,437989,657359,939929,3737581, 6435689,9290431,21084251,26536591,39338069, 44101441,61690919,112805879,289442201,439918931, 1008077071,1103914379,1220664491,1369657969, 1504148881,1779510701,1868223839,2252547431] |