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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 7 |
| 6 | 12 |
| 7 | 21 |
| 8 | 38 |
| 9 | 68 |
| 10 | 120 |
| 11 | 212 |
| 12 | 377 |
| 13 | 670 |
| 14 | 1188 |
| 15 | 2107 |
| 16 | 3740 |
| 17 | 6638 |
| 18 | 11778 |
| 19 | 20898 |
| 20 | 37084 |
| 21 | 65808 |
| 22 | 116775 |
| 23 | 207212 |
| 24 | 367696 |
| 25 | 652478 |
| 26 | 1157815 |
| 27 | 2054524 |
| 28 | 3645730 |
| 29 | 6469316 |
| 30 | 11479734 |
| 31 | 20370656 |
| 32 | 36147506 |
| 33 | 64143372 |
| 34 | 113821732 |
| 35 | 201975429 |
| 36 | 358403220 |
| 37 | 635982680 |
| 38 | 1128544452 |
| 39 | 2002589998 |
[1,1,1,2,4,7,12,21,38,68,120,212,377,670,1188, 2107,3740,6638,11778,20898,37084,65808,116775, 207212,367696,652478,1157815,2054524,3645730, 6469316,11479734,20370656,36147506,64143372, 113821732,201975429,358403220,635982680, 1128544452,2002589998] |