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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 40 |
| 3 | 196 |
| 4 | 844 |
| 5 | 3540 |
| 6 | 14768 |
| 7 | 60384 |
| 8 | 243804 |
| 9 | 974852 |
| 10 | 3911764 |
| 11 | 15653056 |
| 12 | 62623312 |
| 13 | 250548724 |
| 14 | 1002274760 |
| 15 | 4009377540 |
[1,5,40,196,844,3540,14768,60384,243804,974852, 3911764,15653056,62623312,250548724,1002274760, 4009377540] |