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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 13 |
| 4 | 40 |
| 5 | 131 |
| 6 | 452 |
| 7 | 1572 |
| 8 | 5692 |
| 9 | 21031 |
| 10 | 79417 |
| 11 | 302186 |
| 12 | 1169670 |
| 13 | 4574232 |
| 14 | 18083006 |
| 15 | 71931274 |
| 16 | 288765763 |
| 17 | 1166819602 |
| 18 | 4744411047 |
| 19 | 19384558408 |
| 20 | 79648672433 |
| 21 | 328754264401 |
| 22 | 1362556419965 |
| 23 | 5668293251091 |
| 24 | 23670909753372 |
| 25 | 99178834662469 |
| 26 | 416791226821262 |
| 27 | 1756590772659012 |
| 28 | 7424025056902146 |
[1,2,5,13,40,131,452,1572,5692,21031,79417,302186, 1169670,4574232,18083006,71931274,288765763, 1166819602,4744411047,19384558408,79648672433, 328754264401,1362556419965,5668293251091, 23670909753372,99178834662469,416791226821262, 1756590772659012,7424025056902146] |