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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 58 |
| 5 | 202 |
| 6 | 729 |
| 7 | 2695 |
| 8 | 10140 |
| 9 | 38719 |
| 10 | 149682 |
| 11 | 584672 |
| 12 | 2304045 |
| 13 | 9149194 |
| 14 | 36573273 |
| 15 | 147057039 |
| 16 | 594374148 |
| 17 | 2413480053 |
| 18 | 9840832968 |
| 19 | 40276235226 |
| 20 | 165403090815 |
| 21 | 681373222191 |
| 22 | 2814872996190 |
| 23 | 11659083772986 |
| 24 | 48407568680323 |
| 25 | 201431186725778 |
| 26 | 839913707978789 |
[1,2,5,17,58,202,729,2695,10140,38719,149682, 584672,2304045,9149194,36573273,147057039, 594374148,2413480053,9840832968,40276235226, 165403090815,681373222191,2814872996190, 11659083772986,48407568680323,201431186725778, 839913707978789] |