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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 26 |
| 5 | 127 |
| 6 | 746 |
| 7 | 5167 |
| 8 | 41066 |
| 9 | 368047 |
| 10 | 3669866 |
| 11 | 40284847 |
| 12 | 482671466 |
| 13 | 6267305647 |
| 14 | 87660962666 |
| 15 | 1313941673647 |
| 16 | 21010450850666 |
| 17 | 357001369769647 |
| 18 | 6423384156578666 |
| 19 | 122002101778601647 |
| 20 | 2439325392333218666 |
| 21 | 51212944273488041647 |
| 22 | 1126440053169940898666 |
[0,1,2,7,26,127,746,5167,41066,368047,3669866, 40284847,482671466,6267305647,87660962666, 1313941673647,21010450850666,357001369769647, 6423384156578666,122002101778601647, 2439325392333218666,51212944273488041647, 1126440053169940898666] |