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| n | a(n) |
|---|---|
| 1 | 126 |
| 2 | 510 |
| 3 | 1968 |
| 4 | 7722 |
| 5 | 30114 |
| 6 | 117708 |
| 7 | 459690 |
| 8 | 1795842 |
| 9 | 7014816 |
| 10 | 27402198 |
| 11 | 107040102 |
| 12 | 418129380 |
| 13 | 1633329054 |
| 14 | 6380241774 |
| 15 | 24923005584 |
| 16 | 97356232314 |
| 17 | 380300658210 |
| 18 | 1485560712012 |
| 19 | 5803015490538 |
| 20 | 22668201049266 |
| 21 | 88548331298112 |
[126,510,1968,7722,30114,117708,459690,1795842, 7014816,27402198,107040102,418129380,1633329054, 6380241774,24923005584,97356232314,380300658210, 1485560712012,5803015490538,22668201049266, 88548331298112] |