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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 13 |
| 3 | 57 |
| 4 | 255 |
| 5 | 1149 |
| 6 | 5201 |
| 7 | 23607 |
| 8 | 107345 |
| 9 | 488721 |
| 10 | 2227007 |
| 11 | 10154511 |
| 12 | 46323507 |
| 13 | 211396611 |
| 14 | 964966149 |
| 15 | 4405717137 |
| 16 | 20118308687 |
| 17 | 91880092029 |
| 18 | 419657355725 |
| 19 | 1916914550859 |
| 20 | 8756654087981 |
| 21 | 40003289475363 |
| 22 | 182755724339143 |
[1,3,13,57,255,1149,5201,23607,107345,488721, 2227007,10154511,46323507,211396611,964966149, 4405717137,20118308687,91880092029,419657355725, 1916914550859,8756654087981,40003289475363, 182755724339143] |