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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 95 |
| 6 | 471 |
| 7 | 2618 |
| 8 | 16052 |
| 9 | 107313 |
| 10 | 775045 |
| 11 | 6002106 |
| 12 | 49536510 |
| 13 | 433485429 |
| 14 | 4004680967 |
| 15 | 38912323570 |
| 16 | 396393445096 |
| 17 | 4221367056961 |
| 18 | 46878865762185 |
| 19 | 541660919690866 |
| 20 | 6498811587848690 |
| 21 | 80818650742133717 |
| 22 | 1040037672241415947 |
| 23 | 13829246515918840106 |
[1,1,2,6,22,95,471,2618,16052,107313,775045, 6002106,49536510,433485429,4004680967,38912323570, 396393445096,4221367056961,46878865762185, 541660919690866,6498811587848690, 80818650742133717,1040037672241415947, 13829246515918840106] |