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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 23 |
| 3 | 90 |
| 4 | 432 |
| 5 | 2286 |
| 6 | 13176 |
| 7 | 80418 |
| 8 | 513764 |
| 9 | 3400518 |
| 10 | 23167311 |
| 11 | 161640554 |
| 12 | 1150633512 |
| 13 | 8332048638 |
| 14 | 61232315553 |
| 15 | 455830692210 |
| 16 | 3432015694314 |
| 17 | 26101221114582 |
| 18 | 200295455169015 |
| 19 | 1549473966622602 |
| 20 | 12074304397434552 |
| 21 | 94713783502786686 |
| 22 | 747454269790900728 |
[6,23,90,432,2286,13176,80418,513764,3400518, 23167311,161640554,1150633512,8332048638, 61232315553,455830692210,3432015694314, 26101221114582,200295455169015,1549473966622602, 12074304397434552,94713783502786686, 747454269790900728] |