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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 61 |
| 4 | 113 |
| 5 | 53 |
| 6 | 3337 |
| 7 | 12589 |
| 8 | 62945 |
| 9 | 118117 |
| 10 | 328441 |
| 11 | 2690781 |
| 12 | 9259601 |
| 13 | 12743573 |
| 14 | 197935593 |
| 15 | 452807053 |
| 16 | 2264035265 |
| 17 | 7025209029 |
| 18 | 35126045145 |
| 19 | 106910748989 |
| 20 | 809431651889 |
| 21 | 1848135003893 |
| 22 | 9240675019465 |
| 23 | 28611189052909 |
| 24 | 213424689442209 |
| 25 | 785648470500389 |
[0,1,9,61,113,53,3337,12589,62945,118117,328441, 2690781,9259601,12743573,197935593,452807053, 2264035265,7025209029,35126045145,106910748989, 809431651889,1848135003893,9240675019465, 28611189052909,213424689442209,785648470500389] |