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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 9 |
| 3 | 23 |
| 4 | 58 |
| 5 | 149 |
| 6 | 385 |
| 7 | 1000 |
| 8 | 2605 |
| 9 | 6799 |
| 10 | 17766 |
| 11 | 46457 |
| 12 | 121537 |
| 13 | 318044 |
| 14 | 832417 |
| 15 | 2178919 |
| 16 | 5703874 |
| 17 | 14931949 |
| 18 | 39090753 |
| 19 | 102338336 |
| 20 | 267921061 |
| 21 | 701419679 |
| 22 | 1836329614 |
| 23 | 4807555633 |
| 24 | 12586315393 |
| 25 | 32951355124 |
| 26 | 86267692665 |
| 27 | 225851630135 |
[4,9,23,58,149,385,1000,2605,6799,17766,46457, 121537,318044,832417,2178919,5703874,14931949, 39090753,102338336,267921061,701419679,1836329614, 4807555633,12586315393,32951355124,86267692665, 225851630135] |