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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 5 |
| 3 | 7 |
| 4 | 111 |
| 5 | 191 |
| 6 | 1279 |
| 7 | 511 |
| 8 | 31743 |
| 9 | 61439 |
| 10 | 376831 |
| 11 | 458751 |
| 12 | 7077887 |
| 13 | 11534335 |
| 14 | 79691775 |
| 15 | 16777215 |
| 16 | 2113929215 |
| 17 | 4160749567 |
| 18 | 25232932863 |
| 19 | 32212254719 |
| 20 | 472446402559 |
| 21 | 790273982463 |
| 22 | 5360119185407 |
| 23 | 1649267441663 |
| 24 | 134140418588671 |
| 25 | 250688651132927 |
[1,0,5,7,111,191,1279,511,31743,61439,376831, 458751,7077887,11534335,79691775,16777215, 2113929215,4160749567,25232932863,32212254719, 472446402559,790273982463,5360119185407, 1649267441663,134140418588671,250688651132927] |