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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 31 |
| 6 | 107 |
| 7 | 379 |
| 8 | 1556 |
| 9 | 6556 |
| 10 | 31007 |
| 11 | 150349 |
| 12 | 801341 |
| 13 | 4373461 |
| 14 | 25853102 |
| 15 | 156297964 |
| 16 | 1012382291 |
| 17 | 6698486371 |
| 18 | 47089993967 |
| 19 | 337789490599 |
| 20 | 2557480572656 |
| 21 | 19738202807236 |
| 22 | 159928950077327 |
| 23 | 1319703681935929 |
| 24 | 11382338060040761 |
| 25 | 99896787342523081 |
[1,1,2,4,11,31,107,379,1556,6556,31007,150349, 801341,4373461,25853102,156297964,1012382291, 6698486371,47089993967,337789490599,2557480572656, 19738202807236,159928950077327,1319703681935929, 11382338060040761,99896787342523081] |