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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 5 |
| 3 | 7 |
| 4 | 45 |
| 5 | 121 |
| 6 | 533 |
| 7 | 1800 |
| 8 | 7157 |
| 9 | 26239 |
| 10 | 101640 |
| 11 | 384583 |
| 12 | 1483925 |
| 13 | 5693247 |
| 14 | 22013059 |
| 15 | 85076183 |
| 16 | 330014421 |
| 17 | 1281349195 |
| 18 | 4985766650 |
| 19 | 19422653367 |
| 20 | 75775163028 |
| 21 | 295953650376 |
| 22 | 1157212653030 |
| 23 | 4529183513913 |
| 24 | 17743019073381 |
| 25 | 69565441895001 |
[1,0,5,7,45,121,533,1800,7157,26239,101640,384583, 1483925,5693247,22013059,85076183,330014421, 1281349195,4985766650,19422653367,75775163028, 295953650376,1157212653030,4529183513913, 17743019073381,69565441895001] |