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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 38 |
| 4 | 168 |
| 5 | 773 |
| 6 | 3624 |
| 7 | 17170 |
| 8 | 82107 |
| 9 | 395927 |
| 10 | 1919236 |
| 11 | 9343878 |
| 12 | 45659222 |
| 13 | 223779631 |
| 14 | 1099440501 |
| 15 | 5412768563 |
| 16 | 26694974082 |
| 17 | 131851281756 |
| 18 | 652076574086 |
| 19 | 3228477078910 |
| 20 | 15999906011171 |
| 21 | 79360689554108 |
| 22 | 393929523637960 |
| 23 | 1956676225180471 |
| 24 | 9724648269216986 |
| 25 | 48356574924226328 |
| 26 | 240569126976728937 |
[1,2,9,38,168,773,3624,17170,82107,395927,1919236, 9343878,45659222,223779631,1099440501,5412768563, 26694974082,131851281756,652076574086, 3228477078910,15999906011171,79360689554108, 393929523637960,1956676225180471,9724648269216986, 48356574924226328,240569126976728937] |