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| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 10 |
| 2 | 24 |
| 3 | 57 |
| 4 | 135 |
| 5 | 319 |
| 6 | 753 |
| 7 | 1777 |
| 8 | 4193 |
| 9 | 9893 |
| 10 | 23341 |
| 11 | 55069 |
| 12 | 129925 |
| 13 | 306533 |
| 14 | 723205 |
| 15 | 1706261 |
| 16 | 4025589 |
| 17 | 9497589 |
| 18 | 22407701 |
| 19 | 52866581 |
| 20 | 124728341 |
| 21 | 294272085 |
| 22 | 694277333 |
| 23 | 1638011349 |
| 24 | 3864566869 |
| 25 | 9117688405 |
| 26 | 21511399509 |
| 27 | 50751932757 |
| 28 | 119739242325 |
| 29 | 282501283669 |
[4,10,24,57,135,319,753,1777,4193,9893,23341, 55069,129925,306533,723205,1706261,4025589, 9497589,22407701,52866581,124728341,294272085, 694277333,1638011349,3864566869,9117688405, 21511399509,50751932757,119739242325,282501283669] |