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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 36 |
| 6 | 106 |
| 7 | 327 |
| 8 | 1045 |
| 9 | 3433 |
| 10 | 11529 |
| 11 | 39414 |
| 12 | 136733 |
| 13 | 480180 |
| 14 | 1703807 |
| 15 | 6099193 |
| 16 | 22000823 |
| 17 | 79890801 |
| 18 | 291808480 |
| 19 | 1071403389 |
| 20 | 3952020216 |
| 21 | 14638293671 |
| 22 | 54424065467 |
| 23 | 203034222400 |
| 24 | 759790586108 |
| 25 | 2851348853311 |
[1,1,2,5,13,36,106,327,1045,3433,11529,39414, 136733,480180,1703807,6099193,22000823,79890801, 291808480,1071403389,3952020216,14638293671, 54424065467,203034222400,759790586108, 2851348853311] |