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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 21 |
| 3 | 67 |
| 4 | 2059 |
| 5 | 41755 |
| 6 | 986376 |
| 7 | 22238670 |
| 8 | 514990479 |
| 9 | 11843513563 |
| 10 | 273193577866 |
| 11 | 6295815062637 |
| 12 | 145178091690740 |
| 13 | 3347707869286493 |
| 14 | 77204310077778551 |
| 15 | 1780484848971706031 |
| 16 | 41062118413701907548 |
| 17 | 946988189894419322573 |
[0,21,67,2059,41755,986376,22238670,514990479, 11843513563,273193577866,6295815062637, 145178091690740,3347707869286493, 77204310077778551,1780484848971706031, 41062118413701907548,946988189894419322573] |