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| n | a(n) |
|---|---|
| 1 | 28 |
| 2 | 784 |
| 3 | 4000 |
| 4 | 19041 |
| 5 | 75557 |
| 6 | 246087 |
| 7 | 786907 |
| 8 | 2283773 |
| 9 | 6379507 |
| 10 | 17308075 |
| 11 | 45325727 |
| 12 | 117028904 |
| 13 | 296766998 |
| 14 | 743643327 |
| 15 | 1848943779 |
| 16 | 4561246099 |
| 17 | 11201879231 |
| 18 | 27401795310 |
| 19 | 66825353776 |
| 20 | 162629732740 |
| 21 | 395022399526 |
| 22 | 958122589330 |
[28,784,4000,19041,75557,246087,786907,2283773, 6379507,17308075,45325727,117028904,296766998, 743643327,1848943779,4561246099,11201879231, 27401795310,66825353776,162629732740,395022399526, 958122589330] |