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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1326 |
| 3 | 31552 |
| 4 | 240618 |
| 5 | 1452480 |
| 6 | 5030028 |
| 7 | 18128256 |
| 8 | 43527174 |
| 9 | 119299200 |
| 10 | 232127928 |
| 11 | 537564480 |
| 12 | 910537442 |
| 13 | 1881950592 |
| 14 | 2894860164 |
| 15 | 5501926784 |
| 16 | 7880557842 |
| 17 | 14072683776 |
| 18 | 19054928890 |
| 19 | 32409323328 |
| 20 | 42013951980 |
| 21 | 68622996416 |
| 22 | 85866810348 |
| 23 | 135824277120 |
| 24 | 164834073388 |
| 25 | 253845438336 |
| 26 | 300583037448 |
[1,0,1326,31552,240618,1452480,5030028,18128256, 43527174,119299200,232127928,537564480,910537442, 1881950592,2894860164,5501926784,7880557842, 14072683776,19054928890,32409323328,42013951980, 68622996416,85866810348,135824277120,164834073388, 253845438336,300583037448] |