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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 33 |
| 5 | 202 |
| 6 | 1495 |
| 7 | 13107 |
| 8 | 132062 |
| 9 | 1508629 |
| 10 | 19227687 |
| 11 | 270818542 |
| 12 | 4173948097 |
| 13 | 69906444393 |
| 14 | 1263811926338 |
| 15 | 24534217063999 |
| 16 | 508951297964193 |
| 17 | 11236656534791578 |
| 18 | 263054502440239639 |
| 19 | 6508910392250017611 |
| 20 | 169727899004807970782 |
| 21 | 4652123984505282141277 |
| 22 | 133711980572082349859559 |
[1,1,2,7,33,202,1495,13107,132062,1508629, 19227687,270818542,4173948097,69906444393, 1263811926338,24534217063999,508951297964193, 11236656534791578,263054502440239639, 6508910392250017611,169727899004807970782, 4652123984505282141277,133711980572082349859559] |