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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 24 |
| 4 | 58 |
| 5 | 236 |
| 6 | 566 |
| 7 | 2322 |
| 8 | 5578 |
| 9 | 22912 |
| 10 | 55054 |
| 11 | 226148 |
| 12 | 543394 |
| 13 | 2232094 |
| 14 | 5363294 |
| 15 | 22030696 |
| 16 | 52935498 |
| 17 | 217442092 |
| 18 | 522471270 |
| 19 | 2146144946 |
| 20 | 5156771098 |
| 21 | 21182367216 |
| 22 | 50897130430 |
| 23 | 209069141604 |
| 24 | 502352700210 |
| 25 | 2063504305918 |
| 26 | 4958201635918 |
[2,6,24,58,236,566,2322,5578,22912,55054,226148, 543394,2232094,5363294,22030696,52935498, 217442092,522471270,2146144946,5156771098, 21182367216,50897130430,209069141604,502352700210, 2063504305918,4958201635918] |