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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 69 |
| 5 | 233 |
| 6 | 1123 |
| 7 | 4193 |
| 8 | 20365 |
| 9 | 79577 |
| 10 | 389657 |
| 11 | 1576461 |
| 12 | 7753541 |
| 13 | 32101097 |
| 14 | 158408649 |
| 15 | 667616317 |
| 16 | 3302236011 |
| 17 | 14108958387 |
| 18 | 69912164165 |
| 19 | 302004643089 |
| 20 | 1498550596927 |
| 21 | 6531886516731 |
| 22 | 32446754425099 |
| 23 | 142495425257375 |
| 24 | 708461316243015 |
| 25 | 3131209264861149 |
| 26 | 15579022833875687 |
| 27 | 69232956490530607 |
[1,1,5,15,69,233,1123,4193,20365,79577,389657, 1576461,7753541,32101097,158408649,667616317, 3302236011,14108958387,69912164165,302004643089, 1498550596927,6531886516731,32446754425099, 142495425257375,708461316243015,3131209264861149, 15579022833875687,69232956490530607] |