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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 108 |
| 5 | 461 |
| 6 | 2049 |
| 7 | 9263 |
| 8 | 42590 |
| 9 | 197954 |
| 10 | 928679 |
| 11 | 4387192 |
| 12 | 20849236 |
| 13 | 99555146 |
| 14 | 477306096 |
| 15 | 2296206297 |
| 16 | 11078942316 |
| 17 | 53589815828 |
| 18 | 259791441971 |
| 19 | 1261851521328 |
| 20 | 6139539086223 |
| 21 | 29917505988322 |
| 22 | 145984850504298 |
| 23 | 713219844075035 |
| 24 | 3488359044377665 |
| 25 | 17078775447118631 |
| 26 | 83693445393361426 |
[1,2,7,26,108,461,2049,9263,42590,197954,928679, 4387192,20849236,99555146,477306096,2296206297, 11078942316,53589815828,259791441971, 1261851521328,6139539086223,29917505988322, 145984850504298,713219844075035,3488359044377665, 17078775447118631,83693445393361426] |