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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 10 |
| 5 | 26 |
| 6 | 76 |
| 7 | 232 |
| 8 | 764 |
| 9 | 12644 |
| 10 | 61136 |
| 11 | 312676 |
| 12 | 1680592 |
| 13 | 9467680 |
| 14 | 55704104 |
| 15 | 341185496 |
| 16 | 6631556521 |
| 17 | 49294051497 |
| 18 | 380306658250 |
| 19 | 3039453750685 |
| 20 | 25120541332271 |
| 21 | 214363100120051 |
| 22 | 1885987611214092 |
| 23 | 17085579637664715 |
| 24 | 159185637725413675 |
| 25 | 3282701194678476257 |
[1,1,1,1,10,26,76,232,764,12644,61136,312676, 1680592,9467680,55704104,341185496,6631556521, 49294051497,380306658250,3039453750685, 25120541332271,214363100120051,1885987611214092, 17085579637664715,159185637725413675, 3282701194678476257] |