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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 13 |
| 3 | 29 |
| 4 | 142 |
| 5 | 377 |
| 6 | 757 |
| 7 | 3785 |
| 8 | 9841 |
| 9 | 19685 |
| 10 | 98422 |
| 11 | 255905 |
| 12 | 570862 |
| 13 | 2795180 |
| 14 | 7421206 |
| 15 | 14901545 |
| 16 | 74505454 |
| 17 | 193720085 |
| 18 | 387440173 |
| 19 | 1937200865 |
| 20 | 5036722249 |
| 21 | 11235765017 |
| 22 | 55016504566 |
| 23 | 146064945221 |
| 24 | 293292210961 |
| 25 | 1466461054805 |
| 26 | 3812798742493 |
| 27 | 7625597484989 |
[1,5,13,29,142,377,757,3785,9841,19685,98422, 255905,570862,2795180,7421206,14901545,74505454, 193720085,387440173,1937200865,5036722249, 11235765017,55016504566,146064945221,293292210961, 1466461054805,3812798742493,7625597484989] |