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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 11 |
| 4 | 46 |
| 5 | 149 |
| 6 | 663 |
| 7 | 2381 |
| 8 | 10910 |
| 9 | 41487 |
| 10 | 193621 |
| 11 | 764147 |
| 12 | 3610096 |
| 13 | 14634171 |
| 14 | 69738270 |
| 15 | 288397749 |
| 16 | 1383207836 |
| 17 | 5809925465 |
| 18 | 28003318571 |
| 19 | 119097228729 |
| 20 | 576285049578 |
| 21 | 2476095400119 |
| 22 | 12019187733462 |
| 23 | 52084683932849 |
| 24 | 253483958401586 |
| 25 | 1106444794850311 |
| 26 | 5396592007506327 |
| 27 | 23702894459438651 |
[1,1,4,11,46,149,663,2381,10910,41487,193621, 764147,3610096,14634171,69738270,288397749, 1383207836,5809925465,28003318571,119097228729, 576285049578,2476095400119,12019187733462, 52084683932849,253483958401586,1106444794850311, 5396592007506327,23702894459438651] |