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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 26 |
| 3 | 95 |
| 4 | 375 |
| 5 | 1524 |
| 6 | 6170 |
| 7 | 24838 |
| 8 | 100272 |
| 9 | 405068 |
| 10 | 1635673 |
| 11 | 6604612 |
| 12 | 26671526 |
| 13 | 107707761 |
| 14 | 434951162 |
| 15 | 1756450581 |
| 16 | 7093044669 |
| 17 | 28643701145 |
| 18 | 115671273734 |
| 19 | 467113069416 |
| 20 | 1886333772206 |
| 21 | 7617545385889 |
| 22 | 30761787301998 |
| 23 | 124224736350037 |
[4,26,95,375,1524,6170,24838,100272,405068, 1635673,6604612,26671526,107707761,434951162, 1756450581,7093044669,28643701145,115671273734, 467113069416,1886333772206,7617545385889, 30761787301998,124224736350037] |