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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 20 |
| 4 | 51 |
| 5 | 102 |
| 6 | 171 |
| 7 | 244 |
| 8 | 306 |
| 9 | 340 |
| 10 | 3402 |
| 11 | 30928 |
| 12 | 257737 |
| 13 | 1982597 |
| 14 | 14161414 |
| 15 | 94409428 |
| 16 | 590058925 |
| 17 | 3470934853 |
| 18 | 19282971406 |
| 19 | 101489323191 |
| 20 | 507446615959 |
| 21 | 2416412456951 |
| 22 | 10983692986143 |
| 23 | 47755186896276 |
| 24 | 198979945401152 |
[1,6,20,51,102,171,244,306,340,3402,30928,257737, 1982597,14161414,94409428,590058925,3470934853, 19282971406,101489323191,507446615959, 2416412456951,10983692986143,47755186896276, 198979945401152] |