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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 25 |
| 5 | 60 |
| 6 | 135 |
| 7 | 304 |
| 8 | 695 |
| 9 | 1589 |
| 10 | 3570 |
| 11 | 7814 |
| 12 | 16673 |
| 13 | 34916 |
| 14 | 72431 |
| 15 | 150090 |
| 16 | 312277 |
| 17 | 653225 |
| 18 | 1371853 |
| 19 | 2885625 |
| 20 | 6067282 |
| 21 | 12738141 |
| 22 | 26696785 |
| 23 | 55860949 |
| 24 | 116712399 |
| 25 | 243483514 |
| 26 | 507073979 |
| 27 | 1053906817 |
| 28 | 2185668752 |
| 29 | 4523048269 |
[1,3,9,25,60,135,304,695,1589,3570,7814,16673, 34916,72431,150090,312277,653225,1371853,2885625, 6067282,12738141,26696785,55860949,116712399, 243483514,507073979,1053906817,2185668752, 4523048269] |