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| n | a(n) |
|---|---|
| 1 | 28 |
| 2 | 784 |
| 3 | 2654 |
| 4 | 11509 |
| 5 | 59252 |
| 6 | 235872 |
| 7 | 887114 |
| 8 | 3488718 |
| 9 | 13324700 |
| 10 | 49528948 |
| 11 | 184808314 |
| 12 | 687726602 |
| 13 | 2538842648 |
| 14 | 9356257550 |
| 15 | 34457742152 |
| 16 | 126613738962 |
| 17 | 464595415916 |
| 18 | 1703705288482 |
| 19 | 6242056357676 |
| 20 | 22851249560906 |
| 21 | 83609513888316 |
[28,784,2654,11509,59252,235872,887114,3488718, 13324700,49528948,184808314,687726602,2538842648, 9356257550,34457742152,126613738962,464595415916, 1703705288482,6242056357676,22851249560906, 83609513888316] |