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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 456 |
| 3 | 143164 |
| 4 | 75965484 |
| 5 | 55824699632 |
| 6 | 51274161733160 |
| 7 | 55418842406649988 |
| 8 | 67819708829687672202 |
| 9 | 91539069926354814114556 |
| 10 | 133752944758581353219955762 |
| 11 | 208673064320580765981337783096 |
| 12 | 343997162091593719562479905281938 |
| 13 | 594344377404793356460064021706935470 |
[1,4,456,143164,75965484,55824699632, 51274161733160,55418842406649988, 67819708829687672202,91539069926354814114556, 133752944758581353219955762, 208673064320580765981337783096, 343997162091593719562479905281938, 594344377404793356460064021706935470] |