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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 28 |
| 3 | 61 |
| 4 | 206 |
| 5 | 494 |
| 6 | 2095 |
| 7 | 6279 |
| 8 | 21530 |
| 9 | 69977 |
| 10 | 248366 |
| 11 | 813400 |
| 12 | 2838023 |
| 13 | 9457181 |
| 14 | 32284759 |
| 15 | 108523371 |
| 16 | 370702868 |
| 17 | 1251432293 |
| 18 | 4258479323 |
| 19 | 14389442735 |
| 20 | 48816423022 |
| 21 | 165305055080 |
| 22 | 561221682936 |
| 23 | 1901461841900 |
| 24 | 6447263273359 |
[4,28,61,206,494,2095,6279,21530,69977,248366, 813400,2838023,9457181,32284759,108523371, 370702868,1251432293,4258479323,14389442735, 48816423022,165305055080,561221682936, 1901461841900,6447263273359] |