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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 8 |
| 5 | 55 |
| 6 | 348 |
| 7 | 2089 |
| 8 | 10930 |
| 9 | 59507 |
| 10 | 303260 |
| 11 | 1541766 |
| 12 | 7603878 |
| 13 | 39661955 |
| 14 | 193854488 |
| 15 | 942975507 |
| 16 | 4575005798 |
| 17 | 23493563115 |
| 18 | 113291185280 |
| 19 | 541966221369 |
| 20 | 2614491663880 |
| 21 | 13324328958963 |
| 22 | 63919218781860 |
| 23 | 303531944623232 |
| 24 | 1461173082833662 |
| 25 | 7413731116928658 |
| 26 | 35490915453285426 |
[1,8,55,348,2089,10930,59507,303260,1541766, 7603878,39661955,193854488,942975507,4575005798, 23493563115,113291185280,541966221369, 2614491663880,13324328958963,63919218781860, 303531944623232,1461173082833662,7413731116928658, 35490915453285426] |