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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 13 |
| 3 | 57 |
| 4 | 257 |
| 5 | 1185 |
| 6 | 5573 |
| 7 | 26661 |
| 8 | 129437 |
| 9 | 636429 |
| 10 | 3163725 |
| 11 | 15877101 |
| 12 | 80340813 |
| 13 | 409495053 |
| 14 | 2100558429 |
| 15 | 10836262173 |
| 16 | 56184433661 |
| 17 | 292628726205 |
| 18 | 1530338756093 |
| 19 | 8032671187581 |
| 20 | 42304703640701 |
| 21 | 223484135199357 |
| 22 | 1183921500416509 |
| 23 | 6288098247289341 |
[1,3,13,57,257,1185,5573,26661,129437,636429, 3163725,15877101,80340813,409495053,2100558429, 10836262173,56184433661,292628726205, 1530338756093,8032671187581,42304703640701, 223484135199357,1183921500416509,6288098247289341] |