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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 10 |
| 4 | 17 |
| 5 | 38 |
| 6 | 130 |
| 7 | 339 |
| 8 | 754 |
| 9 | 1701 |
| 10 | 3104 |
| 11 | 11588 |
| 12 | 38263 |
| 13 | 108971 |
| 14 | 314890 |
| 15 | 1052619 |
| 16 | 3214632 |
| 17 | 7956589 |
| 18 | 21949555 |
| 19 | 99877775 |
| 20 | 222744644 |
| 21 | 597394254 |
| 22 | 1932355208 |
| 23 | 7250186216 |
| 24 | 17146907278 |
| 25 | 55160980939 |
| 26 | 155891678121 |
| 27 | 508666658006 |
| 28 | 1427745660374 |
| 29 | 4551193622464 |
[2,5,10,17,38,130,339,754,1701,3104,11588,38263, 108971,314890,1052619,3214632,7956589,21949555, 99877775,222744644,597394254,1932355208, 7250186216,17146907278,55160980939,155891678121, 508666658006,1427745660374,4551193622464] |