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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 25 |
| 4 | 62 |
| 5 | 205 |
| 6 | 534 |
| 7 | 2110 |
| 8 | 5844 |
| 9 | 25996 |
| 10 | 75592 |
| 11 | 359256 |
| 12 | 1080592 |
| 13 | 5314480 |
| 14 | 16315424 |
| 15 | 81638240 |
| 16 | 253481024 |
| 17 | 1279358656 |
| 18 | 3996074112 |
| 19 | 20256075136 |
| 20 | 63463817472 |
| 21 | 322392513280 |
| 22 | 1011648561664 |
| 23 | 5144661112320 |
| 24 | 16156254536704 |
| 25 | 82205698518016 |
| 26 | 258259323717632 |
[1,3,9,25,62,205,534,2110,5844,25996,75592,359256, 1080592,5314480,16315424,81638240,253481024, 1279358656,3996074112,20256075136,63463817472, 322392513280,1011648561664,5144661112320, 16156254536704,82205698518016,258259323717632] |