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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 23 |
| 3 | 79 |
| 4 | 89 |
| 5 | 283 |
| 6 | 649 |
| 7 | 1621 |
| 8 | 4209 |
| 9 | 9563 |
| 10 | 25179 |
| 11 | 64825 |
| 12 | 159647 |
| 13 | 400017 |
| 14 | 1006221 |
| 15 | 2575287 |
| 16 | 6472771 |
| 17 | 16199339 |
| 18 | 41000497 |
| 19 | 103869515 |
| 20 | 262156417 |
| 21 | 659973671 |
| 22 | 1666508525 |
| 23 | 4216930049 |
| 24 | 10647519701 |
| 25 | 26860910357 |
| 26 | 67834767395 |
| 27 | 171448094515 |
[0,23,79,89,283,649,1621,4209,9563,25179,64825, 159647,400017,1006221,2575287,6472771,16199339, 41000497,103869515,262156417,659973671,1666508525, 4216930049,10647519701,26860910357,67834767395, 171448094515] |