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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 13 |
| 4 | 31 |
| 5 | 76 |
| 6 | 185 |
| 7 | 451 |
| 8 | 1101 |
| 9 | 2687 |
| 10 | 6569 |
| 11 | 16075 |
| 12 | 39384 |
| 13 | 96594 |
| 14 | 237159 |
| 15 | 582883 |
| 16 | 1434067 |
| 17 | 3531851 |
| 18 | 8707217 |
| 19 | 21488269 |
| 20 | 53084814 |
| 21 | 131276885 |
| 22 | 324981011 |
| 23 | 805345637 |
| 24 | 1997855718 |
| 25 | 4961422706 |
| 26 | 12334208641 |
| 27 | 30695995780 |
| 28 | 76475032893 |
[1,2,7,13,31,76,185,451,1101,2687,6569,16075, 39384,96594,237159,582883,1434067,3531851,8707217, 21488269,53084814,131276885,324981011,805345637, 1997855718,4961422706,12334208641,30695995780, 76475032893] |