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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 37 |
| 4 | 143 |
| 5 | 478 |
| 6 | 1588 |
| 7 | 4910 |
| 8 | 14748 |
| 9 | 42235 |
| 10 | 116910 |
| 11 | 311478 |
| 12 | 803343 |
| 13 | 2004434 |
| 14 | 4853669 |
| 15 | 11414943 |
| 16 | 26127222 |
| 17 | 58267164 |
| 18 | 126811068 |
| 19 | 269647980 |
| 20 | 560935635 |
| 21 | 1142812869 |
| 22 | 2282784640 |
| 23 | 4475122564 |
| 24 | 8618047164 |
| 25 | 16317369805 |
| 26 | 30400944921 |
| 27 | 55776101043 |
| 28 | 100842883244 |
[1,2,10,37,143,478,1588,4910,14748,42235,116910, 311478,803343,2004434,4853669,11414943,26127222, 58267164,126811068,269647980,560935635,1142812869, 2282784640,4475122564,8618047164,16317369805, 30400944921,55776101043,100842883244] |