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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 11 |
| 3 | 3 |
| 4 | 23 |
| 5 | 86 |
| 6 | 238 |
| 7 | 604 |
| 8 | 2492 |
| 9 | 7722 |
| 10 | 26880 |
| 11 | 93816 |
| 12 | 323639 |
| 13 | 1117834 |
| 14 | 3898368 |
| 15 | 13506089 |
| 16 | 46957460 |
| 17 | 163354721 |
| 18 | 567902351 |
| 19 | 1974550100 |
| 20 | 6868633724 |
| 21 | 23885771820 |
| 22 | 83075178134 |
| 23 | 288949706185 |
| 24 | 1004983567658 |
| 25 | 3495450659632 |
| 26 | 12157805469082 |
[0,11,3,23,86,238,604,2492,7722,26880,93816, 323639,1117834,3898368,13506089,46957460, 163354721,567902351,1974550100,6868633724, 23885771820,83075178134,288949706185, 1004983567658,3495450659632,12157805469082] |