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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 23 |
| 5 | 66 |
| 6 | 212 |
| 7 | 686 |
| 8 | 2389 |
| 9 | 8682 |
| 10 | 33160 |
| 11 | 132277 |
| 12 | 550835 |
| 13 | 2384411 |
| 14 | 10709827 |
| 15 | 49782637 |
| 16 | 238998910 |
| 17 | 1182772364 |
| 18 | 6023860266 |
| 19 | 31525780044 |
| 20 | 169316000494 |
| 21 | 932078457785 |
| 22 | 5253664040426 |
| 23 | 30290320077851 |
| 24 | 178480713438362 |
| 25 | 1073918172017297 |
[1,1,3,8,23,66,212,686,2389,8682,33160,132277, 550835,2384411,10709827,49782637,238998910, 1182772364,6023860266,31525780044,169316000494, 932078457785,5253664040426,30290320077851, 178480713438362,1073918172017297] |