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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 25 |
| 4 | 99 |
| 5 | 408 |
| 6 | 1743 |
| 7 | 7592 |
| 8 | 33651 |
| 9 | 151142 |
| 10 | 686105 |
| 11 | 3140899 |
| 12 | 14483587 |
| 13 | 67201968 |
| 14 | 313451655 |
| 15 | 1468679425 |
| 16 | 6909242269 |
| 17 | 32619395556 |
| 18 | 154484826721 |
| 19 | 733698600403 |
| 20 | 3493462038199 |
| 21 | 16672268433976 |
| 22 | 79733503526769 |
| 23 | 382047478275086 |
| 24 | 1833820437688211 |
| 25 | 8816528308289812 |
| 26 | 42450764141048481 |
| 27 | 204679157938797273 |
[1,2,7,25,99,408,1743,7592,33651,151142,686105, 3140899,14483587,67201968,313451655,1468679425, 6909242269,32619395556,154484826721,733698600403, 3493462038199,16672268433976,79733503526769, 382047478275086,1833820437688211,8816528308289812, 42450764141048481,204679157938797273] |