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| n | a(n) |
|---|---|
| 1 | 21 |
| 2 | 119 |
| 3 | 2059 |
| 4 | 11661 |
| 5 | 201761 |
| 6 | 1142659 |
| 7 | 19770519 |
| 8 | 111968921 |
| 9 | 1937309101 |
| 10 | 10971811599 |
| 11 | 189836521379 |
| 12 | 1075125567781 |
| 13 | 18602041786041 |
| 14 | 105351333830939 |
| 15 | 1822810258510639 |
| 16 | 10323355589864241 |
| 17 | 178616803292256581 |
| 18 | 1011583496472864679 |
| 19 | 17502623912382634299 |
| 20 | 99124859298750874301 |
[21,119,2059,11661,201761,1142659,19770519, 111968921,1937309101,10971811599,189836521379, 1075125567781,18602041786041,105351333830939, 1822810258510639,10323355589864241, 178616803292256581,1011583496472864679, 17502623912382634299,99124859298750874301] |