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| n | a(n) |
|---|---|
| 1 | 15 |
| 2 | 120 |
| 3 | 1603 |
| 4 | 21882 |
| 5 | 283450 |
| 6 | 3490152 |
| 7 | 42093113 |
| 8 | 498160278 |
| 9 | 5812405127 |
| 10 | 67071788240 |
| 11 | 766923320987 |
| 12 | 8702848263928 |
| 13 | 98122997204330 |
| 14 | 1100209100745782 |
| 15 | 12277125522368779 |
| 16 | 136425808025932376 |
| 17 | 1510393582783303438 |
[15,120,1603,21882,283450,3490152,42093113, 498160278,5812405127,67071788240,766923320987, 8702848263928,98122997204330,1100209100745782, 12277125522368779,136425808025932376, 1510393582783303438] |