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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 36 |
| 5 | 107 |
| 6 | 447 |
| 7 | 1475 |
| 8 | 6348 |
| 9 | 22453 |
| 10 | 98409 |
| 11 | 363883 |
| 12 | 1617554 |
| 13 | 6174565 |
| 14 | 27735580 |
| 15 | 108449035 |
| 16 | 491170500 |
| 17 | 1956865329 |
| 18 | 8921660445 |
| 19 | 36085841451 |
| 20 | 165420054344 |
| 21 | 677458847443 |
| 22 | 3119736023094 |
| 23 | 12910636874207 |
| 24 | 59685500134828 |
| 25 | 249208756201969 |
| 26 | 1155943476497569 |
| 27 | 4863700769760251 |
| 28 | 22625810378491708 |
[1,1,4,9,36,107,447,1475,6348,22453,98409,363883, 1617554,6174565,27735580,108449035,491170500, 1956865329,8921660445,36085841451,165420054344, 677458847443,3119736023094,12910636874207, 59685500134828,249208756201969,1155943476497569, 4863700769760251,22625810378491708] |