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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 47 |
| 5 | 161 |
| 6 | 580 |
| 7 | 2167 |
| 8 | 8409 |
| 9 | 33338 |
| 10 | 135326 |
| 11 | 558608 |
| 12 | 2341146 |
| 13 | 9943026 |
| 14 | 42693924 |
| 15 | 185206211 |
| 16 | 810338935 |
| 17 | 3573667942 |
| 18 | 15869799860 |
| 19 | 70918166895 |
| 20 | 318720501038 |
| 21 | 1439761710718 |
| 22 | 6534533849551 |
| 23 | 29784956742499 |
| 24 | 136299263675179 |
| 25 | 625984572847841 |
| 26 | 2884631908757017 |
| 27 | 13334144847813943 |
[1,2,5,15,47,161,580,2167,8409,33338,135326, 558608,2341146,9943026,42693924,185206211, 810338935,3573667942,15869799860,70918166895, 318720501038,1439761710718,6534533849551, 29784956742499,136299263675179,625984572847841, 2884631908757017,13334144847813943] |