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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 8 |
| 4 | 36 |
| 5 | 100 |
| 6 | 464 |
| 7 | 1468 |
| 8 | 6965 |
| 9 | 23905 |
| 10 | 114844 |
| 11 | 416216 |
| 12 | 2016743 |
| 13 | 7602555 |
| 14 | 37059549 |
| 15 | 143921898 |
| 16 | 704672428 |
| 17 | 2801020997 |
| 18 | 13760655759 |
| 19 | 55729821081 |
| 20 | 274505700986 |
| 21 | 1128929959934 |
| 22 | 5572377477788 |
| 23 | 23212875492651 |
| 24 | 114773157528287 |
| 25 | 483343556780482 |
| 26 | 2393175485857705 |
| 27 | 10173033731720672 |
| 28 | 50428380890679632 |
[1,1,4,8,36,100,464,1468,6965,23905,114844,416216, 2016743,7602555,37059549,143921898,704672428, 2801020997,13760655759,55729821081,274505700986, 1128929959934,5572377477788,23212875492651, 114773157528287,483343556780482,2393175485857705, 10173033731720672,50428380890679632] |