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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 25 |
| 4 | 80 |
| 5 | 256 |
| 6 | 976 |
| 7 | 3721 |
| 8 | 13725 |
| 9 | 50625 |
| 10 | 189225 |
| 11 | 707281 |
| 12 | 2637376 |
| 13 | 9834496 |
| 14 | 36706880 |
| 15 | 137007025 |
| 16 | 511286105 |
| 17 | 1908029761 |
| 18 | 7120920301 |
| 19 | 26575846441 |
| 20 | 99181976400 |
| 21 | 370150560000 |
| 22 | 1381421480400 |
| 23 | 5155538077561 |
| 24 | 19240724018101 |
[1,5,25,80,256,976,3721,13725,50625,189225,707281, 2637376,9834496,36706880,137007025,511286105, 1908029761,7120920301,26575846441,99181976400, 370150560000,1381421480400,5155538077561, 19240724018101] |