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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 26 |
| 5 | 86 |
| 6 | 392 |
| 7 | 1660 |
| 8 | 9065 |
| 9 | 46705 |
| 10 | 297984 |
| 11 | 1805926 |
| 12 | 13186497 |
| 13 | 91788477 |
| 14 | 754481662 |
| 15 | 5924676900 |
| 16 | 54092804430 |
| 17 | 472512732558 |
| 18 | 4739696836485 |
| 19 | 45540919862179 |
| 20 | 497377234156959 |
| 21 | 5208759709993591 |
| 22 | 61475622078245542 |
| 23 | 696384168181553136 |
| 24 | 8825761698420052542 |
[1,1,3,7,26,86,392,1660,9065,46705,297984,1805926, 13186497,91788477,754481662,5924676900, 54092804430,472512732558,4739696836485, 45540919862179,497377234156959,5208759709993591, 61475622078245542,696384168181553136, 8825761698420052542] |