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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 36 |
| 5 | 116 |
| 6 | 452 |
| 7 | 1613 |
| 8 | 6390 |
| 9 | 24192 |
| 10 | 98022 |
| 11 | 383304 |
| 12 | 1568862 |
| 13 | 6271646 |
| 14 | 25946098 |
| 15 | 105492537 |
| 16 | 439845324 |
| 17 | 1809101840 |
| 18 | 7589944482 |
| 19 | 31515272858 |
| 20 | 132927819060 |
| 21 | 556072151042 |
| 22 | 2355529776828 |
| 23 | 9913350863408 |
| 24 | 42150753753288 |
| 25 | 178288844129100 |
| 26 | 760495077330246 |
| 27 | 3230288897150356 |
| 28 | 13817292281947918 |
[1,1,4,9,36,116,452,1613,6390,24192,98022,383304, 1568862,6271646,25946098,105492537,439845324, 1809101840,7589944482,31515272858,132927819060, 556072151042,2355529776828,9913350863408, 42150753753288,178288844129100,760495077330246, 3230288897150356,13817292281947918] |