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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 16 |
| 4 | 47 |
| 5 | 121 |
| 6 | 322 |
| 7 | 841 |
| 8 | 2207 |
| 9 | 5776 |
| 10 | 15127 |
| 11 | 39601 |
| 12 | 103682 |
| 13 | 271441 |
| 14 | 710647 |
| 15 | 1860496 |
| 16 | 4870847 |
| 17 | 12752041 |
| 18 | 33385282 |
| 19 | 87403801 |
| 20 | 228826127 |
| 21 | 599074576 |
| 22 | 1568397607 |
| 23 | 4106118241 |
| 24 | 10749957122 |
| 25 | 28143753121 |
| 26 | 73681302247 |
| 27 | 192900153616 |
| 28 | 505019158607 |
[1,7,16,47,121,322,841,2207,5776,15127,39601, 103682,271441,710647,1860496,4870847,12752041, 33385282,87403801,228826127,599074576,1568397607, 4106118241,10749957122,28143753121,73681302247, 192900153616,505019158607] |