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| n | a(n) |
|---|---|
| 3 | 12 |
| 4 | 198 |
| 5 | 2520 |
| 6 | 29886 |
| 7 | 347907 |
| 8 | 4048966 |
| 9 | 47431488 |
| 10 | 560528820 |
| 11 | 6684500548 |
| 12 | 80402461416 |
| 13 | 974694481735 |
| 14 | 11899112853684 |
| 15 | 146175947513247 |
| 16 | 1805742311925206 |
| 17 | 22417900292210960 |
| 18 | 279556262002954608 |
| 19 | 3500139320096264886 |
| 20 | 43982137867266022438 |
| 21 | 554494988892196104240 |
[12,198,2520,29886,347907,4048966,47431488, 560528820,6684500548,80402461416,974694481735, 11899112853684,146175947513247,1805742311925206, 22417900292210960,279556262002954608, 3500139320096264886,43982137867266022438, 554494988892196104240] |