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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 6 |
| 3 | 9 |
| 4 | 25 |
| 5 | 60 |
| 6 | 160 |
| 7 | 396 |
| 8 | 996 |
| 9 | 2480 |
| 10 | 6213 |
| 11 | 15537 |
| 12 | 38935 |
| 13 | 97574 |
| 14 | 244521 |
| 15 | 612350 |
| 16 | 1533665 |
| 17 | 3841552 |
| 18 | 9623474 |
| 19 | 24106566 |
| 20 | 60386058 |
| 21 | 151263372 |
| 22 | 378906980 |
| 23 | 949140173 |
| 24 | 2377551381 |
| 25 | 5955661956 |
| 26 | 14918670478 |
| 27 | 37370561312 |
| 28 | 93611479464 |
| 29 | 234492365157 |
[3,6,9,25,60,160,396,996,2480,6213,15537,38935, 97574,244521,612350,1533665,3841552,9623474, 24106566,60386058,151263372,378906980,949140173, 2377551381,5955661956,14918670478,37370561312, 93611479464,234492365157] |