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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 15 |
| 4 | 29 |
| 5 | 63 |
| 6 | 199 |
| 7 | 629 |
| 8 | 1837 |
| 9 | 5397 |
| 10 | 15855 |
| 11 | 46857 |
| 12 | 139131 |
| 13 | 411859 |
| 14 | 1218209 |
| 15 | 3604353 |
| 16 | 10667225 |
| 17 | 31574175 |
| 18 | 93448425 |
| 19 | 276561899 |
| 20 | 818499247 |
| 21 | 2422423269 |
| 22 | 7169412933 |
| 23 | 21218549729 |
| 24 | 62798160031 |
| 25 | 185856754621 |
| 26 | 550059982899 |
[1,7,15,29,63,199,629,1837,5397,15855,46857, 139131,411859,1218209,3604353,10667225,31574175, 93448425,276561899,818499247,2422423269, 7169412933,21218549729,62798160031,185856754621, 550059982899] |