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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 13 |
| 4 | 65 |
| 5 | 330 |
| 6 | 1297 |
| 7 | 6393 |
| 8 | 30904 |
| 9 | 154041 |
| 10 | 764894 |
| 11 | 3804884 |
| 12 | 18978589 |
| 13 | 94697319 |
| 14 | 472770928 |
| 15 | 2360757090 |
| 16 | 11789229577 |
| 17 | 58877258002 |
| 18 | 294049444613 |
| 19 | 1468594070621 |
| 20 | 7334774136424 |
| 21 | 36633069686965 |
| 22 | 182962072923069 |
| 23 | 913796219872826 |
[1,6,13,65,330,1297,6393,30904,154041,764894, 3804884,18978589,94697319,472770928,2360757090, 11789229577,58877258002,294049444613, 1468594070621,7334774136424,36633069686965, 182962072923069,913796219872826] |