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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 26 |
| 4 | 85 |
| 5 | 264 |
| 6 | 803 |
| 7 | 2422 |
| 8 | 7281 |
| 9 | 21860 |
| 10 | 65599 |
| 11 | 196818 |
| 12 | 590477 |
| 13 | 1771456 |
| 14 | 5314395 |
| 15 | 15943214 |
| 16 | 47829673 |
| 17 | 143489052 |
| 18 | 430467191 |
| 19 | 1291401610 |
| 20 | 3874204869 |
| 21 | 11622614648 |
| 22 | 34867843987 |
| 23 | 104603532006 |
| 24 | 313810596065 |
| 25 | 941431788244 |
| 26 | 2824295364783 |
| 27 | 8472886094402 |
[1,7,26,85,264,803,2422,7281,21860,65599,196818, 590477,1771456,5314395,15943214,47829673, 143489052,430467191,1291401610,3874204869, 11622614648,34867843987,104603532006,313810596065, 941431788244,2824295364783,8472886094402] |