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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 42 |
| 4 | 253 |
| 5 | 1519 |
| 6 | 9114 |
| 7 | 54685 |
| 8 | 328111 |
| 9 | 1968666 |
| 10 | 11811997 |
| 11 | 70871983 |
| 12 | 425231898 |
| 13 | 2551391389 |
| 14 | 15308348335 |
| 15 | 91850090010 |
| 16 | 551100540061 |
| 17 | 3306603240367 |
| 18 | 19839619442202 |
| 19 | 119037716653213 |
| 20 | 714226299919279 |
| 21 | 4285357799515674 |
| 22 | 25712146797094045 |
| 23 | 154272880782564271 |
[1,7,42,253,1519,9114,54685,328111,1968666, 11811997,70871983,425231898,2551391389, 15308348335,91850090010,551100540061, 3306603240367,19839619442202,119037716653213, 714226299919279,4285357799515674, 25712146797094045,154272880782564271] |