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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 45 |
| 4 | 224 |
| 5 | 1045 |
| 6 | 4680 |
| 7 | 20377 |
| 8 | 86912 |
| 9 | 364905 |
| 10 | 1513160 |
| 11 | 6211909 |
| 12 | 25290720 |
| 13 | 102251773 |
| 14 | 410963336 |
| 15 | 1643288625 |
| 16 | 6541692416 |
| 17 | 25939798993 |
| 18 | 102503274120 |
| 19 | 403800061789 |
| 20 | 1586318259680 |
| 21 | 6216231359205 |
| 22 | 24304019419592 |
| 23 | 94826736906697 |
| 24 | 369285078314880 |
| 25 | 1435615286196025 |
[1,8,45,224,1045,4680,20377,86912,364905,1513160, 6211909,25290720,102251773,410963336,1643288625, 6541692416,25939798993,102503274120,403800061789, 1586318259680,6216231359205,24304019419592, 94826736906697,369285078314880,1435615286196025] |