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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 30 |
| 4 | 133 |
| 5 | 566 |
| 6 | 2617 |
| 7 | 11763 |
| 8 | 55530 |
| 9 | 256938 |
| 10 | 1227867 |
| 11 | 5781928 |
| 12 | 27850891 |
| 13 | 132672582 |
| 14 | 642602461 |
| 15 | 3085978055 |
| 16 | 15007566746 |
| 17 | 72497656217 |
| 18 | 353657229891 |
| 19 | 1716074631939 |
| 20 | 8391740124484 |
| 21 | 40861709568748 |
| 22 | 200210893873034 |
| 23 | 977590879486953 |
| 24 | 4797722906700485 |
| 25 | 23479286547998069 |
| 26 | 115387185124601996 |
[1,2,8,30,133,566,2617,11763,55530,256938,1227867, 5781928,27850891,132672582,642602461,3085978055, 15007566746,72497656217,353657229891, 1716074631939,8391740124484,40861709568748, 200210893873034,977590879486953,4797722906700485, 23479286547998069,115387185124601996] |