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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 19 |
| 4 | 78 |
| 5 | 359 |
| 6 | 1526 |
| 7 | 6544 |
| 8 | 27595 |
| 9 | 116025 |
| 10 | 480396 |
| 11 | 1973735 |
| 12 | 8049327 |
| 13 | 32661563 |
| 14 | 131897421 |
| 15 | 531069857 |
[1,4,19,78,359,1526,6544,27595,116025,480396, 1973735,8049327,32661563,131897421,531069857] |