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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 14 |
| 3 | 63 |
| 4 | 298 |
| 5 | 1428 |
| 6 | 6906 |
| 7 | 33653 |
| 8 | 164836 |
| 9 | 810060 |
| 10 | 3993446 |
| 11 | 19727978 |
| 12 | 97630392 |
| 13 | 483860652 |
| 14 | 2400763156 |
| 15 | 11923446689 |
| 16 | 59266186460 |
| 17 | 294785399216 |
| 18 | 1467099385086 |
| 19 | 7305154655534 |
| 20 | 36390338352432 |
| 21 | 181345090767820 |
| 22 | 903997336345772 |
| 23 | 4507679568564746 |
| 24 | 22482713911686816 |
| 25 | 112160886877865048 |
[1,3,14,63,298,1428,6906,33653,164836,810060, 3993446,19727978,97630392,483860652,2400763156, 11923446689,59266186460,294785399216, 1467099385086,7305154655534,36390338352432, 181345090767820,903997336345772,4507679568564746, 22482713911686816,112160886877865048] |