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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 10 |
| 3 | 20 |
| 4 | 26 |
| 5 | 169 |
| 6 | 475 |
| 7 | 1234 |
| 8 | 5007 |
| 9 | 16422 |
| 10 | 51196 |
| 11 | 182859 |
| 12 | 619558 |
| 13 | 2064945 |
| 14 | 7171550 |
| 15 | 24597409 |
| 16 | 83961318 |
| 17 | 290423638 |
| 18 | 1002057750 |
| 19 | 3452837246 |
| 20 | 11953834123 |
| 21 | 41373636357 |
| 22 | 143157425820 |
| 23 | 496258006589 |
| 24 | 1720526318696 |
| 25 | 5965062389328 |
[2,10,20,26,169,475,1234,5007,16422,51196,182859, 619558,2064945,7171550,24597409,83961318, 290423638,1002057750,3452837246,11953834123, 41373636357,143157425820,496258006589, 1720526318696,5965062389328] |