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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 11 |
| 3 | 51 |
| 4 | 216 |
| 5 | 861 |
| 6 | 3477 |
| 7 | 13367 |
| 8 | 50377 |
| 9 | 184667 |
| 10 | 664484 |
| 11 | 2345230 |
| 12 | 8142476 |
| 13 | 27825576 |
| 14 | 93750686 |
| 15 | 311682789 |
| 16 | 1023547782 |
| 17 | 3322634928 |
| 18 | 10669887669 |
| 19 | 33916213669 |
| 20 | 106776876109 |
| 21 | 333111724130 |
| 22 | 1030264525744 |
| 23 | 3160359629535 |
| 24 | 9618807643826 |
| 25 | 29057370625281 |
| 26 | 87153154537437 |
[1,1,11,51,216,861,3477,13367,50377,184667,664484, 2345230,8142476,27825576,93750686,311682789, 1023547782,3322634928,10669887669,33916213669, 106776876109,333111724130,1030264525744, 3160359629535,9618807643826,29057370625281, 87153154537437] |