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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 26 |
| 5 | 78 |
| 6 | 234 |
| 7 | 702 |
| 8 | 2103 |
| 9 | 6309 |
| 10 | 18927 |
| 11 | 56781 |
| 12 | 170334 |
| 13 | 511002 |
| 14 | 1533006 |
| 15 | 4599018 |
| 16 | 13797028 |
| 17 | 41391084 |
| 18 | 124173252 |
| 19 | 372519756 |
| 20 | 1117559190 |
| 21 | 3352677570 |
| 22 | 10058032710 |
| 23 | 30174098130 |
| 24 | 90522294156 |
| 25 | 271566882468 |
| 26 | 814700647404 |
| 27 | 2444101942212 |
| 28 | 7332305825934 |
| 29 | 21996917477802 |
[1,3,9,26,78,234,702,2103,6309,18927,56781,170334, 511002,1533006,4599018,13797028,41391084, 124173252,372519756,1117559190,3352677570, 10058032710,30174098130,90522294156,271566882468, 814700647404,2444101942212,7332305825934, 21996917477802] |