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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 10 |
| 4 | 15 |
| 5 | 1155 |
| 6 | 1365 |
| 7 | 12155 |
| 8 | 1616615 |
| 9 | 37182145 |
| 10 | 11849255 |
| 11 | 33426748355 |
| 12 | 247357937827 |
| 13 | 10141675450907 |
| 14 | 25652473199353 |
| 15 | 2928046583754721 |
| 16 | 155186468939000213 |
| 17 | 223317113839049087 |
| 18 | 558516101711461766587 |
| 19 | 796182527971658263007 |
| 20 | 241532826894674874877669 |
| 21 | 430046252763689411367557 |
[1,6,10,15,1155,1365,12155,1616615,37182145, 11849255,33426748355,247357937827,10141675450907, 25652473199353,2928046583754721, 155186468939000213,223317113839049087, 558516101711461766587,796182527971658263007, 241532826894674874877669,430046252763689411367557] |