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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 67 |
| 3 | 1993 |
| 4 | 43891 |
| 5 | 836521 |
| 6 | 14764627 |
| 7 | 249723433 |
| 8 | 4123297651 |
| 9 | 67157947561 |
| 10 | 1085384064787 |
| 11 | 17464790421673 |
| 12 | 280328391247411 |
| 13 | 4493290901135401 |
| 14 | 71964955947764947 |
| 15 | 1152089156508284713 |
| 16 | 18439265231953981171 |
| 17 | 295080697103288816041 |
| 18 | 4721762414918959913107 |
[1,67,1993,43891,836521,14764627,249723433, 4123297651,67157947561,1085384064787, 17464790421673,280328391247411,4493290901135401, 71964955947764947,1152089156508284713, 18439265231953981171,295080697103288816041, 4721762414918959913107] |