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| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 17 |
| 6 | 131 |
| 7 | 709 |
| 8 | 3350 |
| 9 | 14337 |
| 10 | 57507 |
| 11 | 218746 |
| 12 | 803384 |
| 13 | 2870707 |
| 14 | 10044838 |
| 15 | 34548917 |
| 16 | 117224825 |
| 17 | 393290329 |
| 18 | 1307200931 |
| 19 | 4310348599 |
| 20 | 14116544717 |
| 21 | 45959805027 |
| 22 | 148860350902 |
| 23 | 479938536114 |
| 24 | 1541025955958 |
| 25 | 4929773150983 |
[1,17,131,709,3350,14337,57507,218746,803384, 2870707,10044838,34548917,117224825,393290329, 1307200931,4310348599,14116544717,45959805027, 148860350902,479938536114,1541025955958, 4929773150983] |