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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 13 |
| 3 | 8 |
| 4 | 68 |
| 5 | 299 |
| 6 | 1351 |
| 7 | 6653 |
| 8 | 30441 |
| 9 | 146175 |
| 10 | 682879 |
| 11 | 3234177 |
| 12 | 15226483 |
| 13 | 71859897 |
| 14 | 338825989 |
| 15 | 1598126524 |
| 16 | 7536923120 |
| 17 | 35546600366 |
| 18 | 167645751951 |
| 19 | 790663538862 |
| 20 | 3728968861295 |
| 21 | 17586797354805 |
| 22 | 82943890400479 |
| 23 | 391184964947659 |
[0,13,8,68,299,1351,6653,30441,146175,682879, 3234177,15226483,71859897,338825989,1598126524, 7536923120,35546600366,167645751951,790663538862, 3728968861295,17586797354805,82943890400479, 391184964947659] |