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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 9 |
| 3 | 21 |
| 4 | 51 |
| 5 | 127 |
| 6 | 324 |
| 7 | 844 |
| 8 | 2242 |
| 9 | 6062 |
| 10 | 16655 |
| 11 | 46411 |
| 12 | 130937 |
| 13 | 373349 |
| 14 | 1074194 |
| 15 | 3114146 |
| 16 | 9085176 |
| 17 | 26643492 |
| 18 | 78470989 |
| 19 | 231925649 |
| 20 | 687430207 |
| 21 | 2042284587 |
| 22 | 6078844480 |
| 23 | 18121207896 |
| 24 | 54086361422 |
| 25 | 161592030394 |
| 26 | 483170313579 |
[4,9,21,51,127,324,844,2242,6062,16655,46411, 130937,373349,1074194,3114146,9085176,26643492, 78470989,231925649,687430207,2042284587, 6078844480,18121207896,54086361422,161592030394, 483170313579] |