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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 46 |
| 6 | 173 |
| 7 | 733 |
| 8 | 3436 |
| 9 | 17572 |
| 10 | 96997 |
| 11 | 573268 |
| 12 | 3604687 |
| 13 | 23990345 |
| 14 | 168254444 |
| 15 | 1238889493 |
| 16 | 9546211068 |
| 17 | 76761000444 |
| 18 | 642524333589 |
| 19 | 5586361188966 |
| 20 | 50351455288661 |
| 21 | 469653513479395 |
| 22 | 4526242614854118 |
| 23 | 45005754238016688 |
[1,1,2,5,14,46,173,733,3436,17572,96997,573268, 3604687,23990345,168254444,1238889493,9546211068, 76761000444,642524333589,5586361188966, 50351455288661,469653513479395,4526242614854118, 45005754238016688] |