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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 9 |
| 3 | 21 |
| 4 | 51 |
| 5 | 127 |
| 6 | 324 |
| 7 | 844 |
| 8 | 2243 |
| 9 | 6073 |
| 10 | 16737 |
| 11 | 46905 |
| 12 | 133555 |
| 13 | 386047 |
| 14 | 1131958 |
| 15 | 3364454 |
| 16 | 10129563 |
| 17 | 30871733 |
| 18 | 95176427 |
| 19 | 296618011 |
| 20 | 933821451 |
| 21 | 2967726939 |
| 22 | 9514201392 |
| 23 | 30747183016 |
| 24 | 100097739315 |
| 25 | 328049191105 |
| 26 | 1081610514581 |
[4,9,21,51,127,324,844,2243,6073,16737,46905, 133555,386047,1131958,3364454,10129563,30871733, 95176427,296618011,933821451,2967726939, 9514201392,30747183016,100097739315,328049191105, 1081610514581] |