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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 15 |
| 2 | 257 |
| 3 | 1639 |
| 4 | 6369 |
| 5 | 18551 |
| 6 | 44785 |
| 7 | 94767 |
| 8 | 181889 |
| 9 | 323839 |
| 10 | 543201 |
| 11 | 868055 |
| 12 | 1332577 |
| 13 | 1977639 |
| 14 | 2851409 |
| 15 | 4009951 |
| 16 | 5517825 |
| 17 | 7448687 |
| 18 | 9885889 |
| 19 | 12923079 |
| 20 | 16664801 |
| 21 | 21227095 |
| 22 | 26738097 |
| 23 | 33338639 |
| 24 | 41182849 |
| 25 | 50438751 |
| 26 | 61288865 |
| 27 | 73930807 |
| 28 | 88577889 |
| 29 | 105459719 |
[1,15,257,1639,6369,18551,44785,94767,181889, 323839,543201,868055,1332577,1977639,2851409, 4009951,5517825,7448687,9885889,12923079,16664801, 21227095,26738097,33338639,41182849,50438751, 61288865,73930807,88577889,105459719] |