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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 25 |
| 3 | 68 |
| 4 | 193 |
| 5 | 544 |
| 6 | 1539 |
| 7 | 4355 |
| 8 | 12332 |
| 9 | 34907 |
| 10 | 98797 |
| 11 | 279622 |
| 12 | 791433 |
| 13 | 2240071 |
| 14 | 6340292 |
| 15 | 17945485 |
| 16 | 50792619 |
| 17 | 143762646 |
| 18 | 406903731 |
| 19 | 1151694633 |
| 20 | 3259740340 |
| 21 | 9226322979 |
| 22 | 26114053785 |
| 23 | 73912847850 |
| 24 | 209201878257 |
| 25 | 592122035615 |
[4,25,68,193,544,1539,4355,12332,34907,98797, 279622,791433,2240071,6340292,17945485,50792619, 143762646,406903731,1151694633,3259740340, 9226322979,26114053785,73912847850,209201878257, 592122035615] |