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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 7 |
| 3 | 32 |
| 4 | 176 |
| 5 | 1066 |
| 6 | 6935 |
| 7 | 47216 |
| 8 | 332700 |
| 9 | 2404818 |
| 10 | 17734668 |
| 11 | 132901644 |
| 12 | 1009161505 |
| 13 | 7747608480 |
| 14 | 60037905076 |
| 15 | 468987635982 |
| 16 | 3689066578347 |
| 17 | 29195587558726 |
| 18 | 232303316402615 |
| 19 | 1857264782113562 |
| 20 | 14912673794505898 |
| 21 | 120203145484455930 |
| 22 | 972291038495626309 |
[2,7,32,176,1066,6935,47216,332700,2404818, 17734668,132901644,1009161505,7747608480, 60037905076,468987635982,3689066578347, 29195587558726,232303316402615,1857264782113562, 14912673794505898,120203145484455930, 972291038495626309] |