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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 17 |
| 7 | 38 |
| 8 | 92 |
| 9 | 238 |
| 10 | 643 |
| 11 | 1790 |
| 12 | 5076 |
| 13 | 14573 |
| 14 | 42241 |
| 15 | 123484 |
| 16 | 364052 |
| 17 | 1082602 |
| 18 | 3247759 |
| 19 | 9829820 |
| 20 | 30019326 |
| 21 | 92517644 |
| 22 | 287805801 |
| 23 | 903822922 |
| 24 | 2865339252 |
| 25 | 9168572009 |
| 26 | 29601077285 |
| 27 | 96377791839 |
| 28 | 316264456921 |
[1,1,1,2,4,8,17,38,92,238,643,1790,5076,14573, 42241,123484,364052,1082602,3247759,9829820, 30019326,92517644,287805801,903822922,2865339252, 9168572009,29601077285,96377791839,316264456921] |