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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 30 |
| 5 | 95 |
| 6 | 373 |
| 7 | 1337 |
| 8 | 5491 |
| 9 | 20879 |
| 10 | 87823 |
| 11 | 348878 |
| 12 | 1495592 |
| 13 | 6116233 |
| 14 | 26582687 |
| 15 | 111153122 |
| 16 | 488390316 |
| 17 | 2076955693 |
| 18 | 9206018343 |
| 19 | 39681877464 |
| 20 | 177159455338 |
| 21 | 772030567083 |
| 22 | 3467620937271 |
| 23 | 15248904120655 |
| 24 | 68844612742745 |
| 25 | 305061781752215 |
| 26 | 1383396232352037 |
| 27 | 6170031420068042 |
| 28 | 28088366503307858 |
[1,1,3,8,30,95,373,1337,5491,20879,87823,348878, 1495592,6116233,26582687,111153122,488390316, 2076955693,9206018343,39681877464,177159455338, 772030567083,3467620937271,15248904120655, 68844612742745,305061781752215,1383396232352037, 6170031420068042,28088366503307858] |