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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 29 |
| 4 | 96 |
| 5 | 319 |
| 6 | 1059 |
| 7 | 3513 |
| 8 | 11651 |
| 9 | 38640 |
| 10 | 128149 |
| 11 | 425007 |
| 12 | 1409541 |
| 13 | 4674761 |
| 14 | 15503904 |
| 15 | 51418891 |
| 16 | 170531391 |
| 17 | 565569477 |
| 18 | 1875718199 |
| 19 | 6220842720 |
| 20 | 20631502201 |
| 21 | 68424633483 |
| 22 | 226931147409 |
| 23 | 752619970949 |
| 24 | 2496073488096 |
| 25 | 8278258747399 |
| 26 | 27454948027659 |
[1,3,9,29,96,319,1059,3513,11651,38640,128149, 425007,1409541,4674761,15503904,51418891, 170531391,565569477,1875718199,6220842720, 20631502201,68424633483,226931147409,752619970949, 2496073488096,8278258747399,27454948027659] |