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| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 7 |
| 2 | 22 |
| 3 | 58 |
| 4 | 160 |
| 5 | 436 |
| 6 | 1192 |
| 7 | 3256 |
| 8 | 8896 |
| 9 | 24304 |
| 10 | 66400 |
| 11 | 181408 |
| 12 | 495616 |
| 13 | 1354048 |
| 14 | 3699328 |
| 15 | 10106752 |
| 16 | 27612160 |
| 17 | 75437824 |
| 18 | 206099968 |
| 19 | 563075584 |
| 20 | 1538351104 |
| 21 | 4202853376 |
| 22 | 11482408960 |
| 23 | 31370524672 |
| 24 | 85705867264 |
| 25 | 234152783872 |
| 26 | 639717302272 |
| 27 | 1747740172288 |
| 28 | 4774914949120 |
[4,7,22,58,160,436,1192,3256,8896,24304,66400, 181408,495616,1354048,3699328,10106752,27612160, 75437824,206099968,563075584,1538351104, 4202853376,11482408960,31370524672,85705867264, 234152783872,639717302272,1747740172288, 4774914949120] |