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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 3 |
| 2 | 6 |
| 3 | 9 |
| 4 | 17 |
| 5 | 29 |
| 6 | 52 |
| 7 | 90 |
| 8 | 159 |
| 9 | 278 |
| 10 | 489 |
| 11 | 857 |
| 12 | 1505 |
| 13 | 2640 |
| 14 | 4634 |
| 15 | 8131 |
| 16 | 14270 |
| 17 | 25041 |
| 18 | 43945 |
| 19 | 77117 |
| 20 | 135332 |
| 21 | 237490 |
| 22 | 416767 |
| 23 | 731374 |
| 24 | 1283473 |
| 25 | 2252337 |
| 26 | 3952577 |
| 27 | 6936288 |
| 28 | 12172338 |
| 29 | 21360963 |
| 30 | 37485878 |
| 31 | 65783129 |
| 32 | 115441345 |
| 33 | 202585437 |
[2,3,6,9,17,29,52,90,159,278,489,857,1505,2640, 4634,8131,14270,25041,43945,77117,135332,237490, 416767,731374,1283473,2252337,3952577,6936288, 12172338,21360963,37485878,65783129,115441345, 202585437] |