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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 75 |
| 4 | 425 |
| 5 | 2189 |
| 6 | 12353 |
| 7 | 63833 |
| 8 | 346973 |
| 9 | 1805573 |
| 10 | 9565325 |
| 11 | 49069517 |
| 12 | 257289529 |
| 13 | 1307750129 |
| 14 | 6723491129 |
| 15 | 34024174649 |
| 16 | 172873744739 |
| 17 | 865954792079 |
| 18 | 4359881882579 |
| 19 | 21679061144579 |
| 20 | 108108834714719 |
| 21 | 534409071271199 |
| 22 | 2642716232918639 |
| 23 | 12975671796056639 |
| 24 | 63765647596939139 |
[1,3,15,75,425,2189,12353,63833,346973,1805573, 9565325,49069517,257289529,1307750129,6723491129, 34024174649,172873744739,865954792079, 4359881882579,21679061144579,108108834714719, 534409071271199,2642716232918639, 12975671796056639,63765647596939139] |