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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 28 |
| 5 | 95 |
| 6 | 353 |
| 7 | 1435 |
| 8 | 6340 |
| 9 | 30205 |
| 10 | 154059 |
| 11 | 836181 |
| 12 | 4805816 |
| 13 | 29125915 |
| 14 | 185474289 |
| 15 | 1237159447 |
| 16 | 8620179448 |
| 17 | 62589847993 |
| 18 | 472554134275 |
| 19 | 3702702752513 |
| 20 | 30057098645316 |
| 21 | 252375781238167 |
| 22 | 2188733915100465 |
| 23 | 19579797280231795 |
| 24 | 180453411239741852 |
| 25 | 1711498126672376373 |
[0,1,3,9,28,95,353,1435,6340,30205,154059,836181, 4805816,29125915,185474289,1237159447,8620179448, 62589847993,472554134275,3702702752513, 30057098645316,252375781238167,2188733915100465, 19579797280231795,180453411239741852, 1711498126672376373] |