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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 5 |
| 3 | 10 |
| 4 | 19 |
| 5 | 34 |
| 6 | 63 |
| 7 | 116 |
| 8 | 213 |
| 9 | 392 |
| 10 | 721 |
| 11 | 1326 |
| 12 | 2439 |
| 13 | 4486 |
| 14 | 8251 |
| 15 | 15176 |
| 16 | 27913 |
| 17 | 51340 |
| 18 | 94429 |
| 19 | 173682 |
| 20 | 319451 |
| 21 | 587562 |
| 22 | 1080695 |
| 23 | 1987708 |
| 24 | 3655965 |
| 25 | 6724368 |
| 26 | 12368041 |
| 27 | 22748374 |
| 28 | 41840783 |
| 29 | 76957198 |
| 30 | 141546355 |
[1,4,5,10,19,34,63,116,213,392,721,1326,2439,4486, 8251,15176,27913,51340,94429,173682,319451,587562, 1080695,1987708,3655965,6724368,12368041,22748374, 41840783,76957198,141546355] |