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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 45 |
| 4 | 302 |
| 5 | 1648 |
| 6 | 7594 |
| 7 | 31152 |
| 8 | 119656 |
| 9 | 446500 |
| 10 | 1658080 |
| 11 | 6210762 |
| 12 | 23592940 |
| 13 | 90908854 |
| 14 | 354490210 |
| 15 | 1394647332 |
| 16 | 5520750316 |
[1,7,45,302,1648,7594,31152,119656,446500,1658080, 6210762,23592940,90908854,354490210,1394647332, 5520750316] |