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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 39 |
| 5 | 155 |
| 6 | 629 |
| 7 | 2635 |
| 8 | 11375 |
| 9 | 49775 |
| 10 | 221993 |
| 11 | 1000469 |
| 12 | 4559119 |
| 13 | 20954301 |
| 14 | 97007355 |
| 15 | 452068093 |
| 16 | 2117955301 |
| 17 | 9972403285 |
| 18 | 47151732371 |
| 19 | 223801633257 |
| 20 | 1065825239793 |
| 21 | 5091269173915 |
| 22 | 24386527347883 |
| 23 | 117095676603227 |
| 24 | 563513272181635 |
| 25 | 2717367767033319 |
| 26 | 13128069939371165 |
| 27 | 63531808704306035 |
[1,1,3,11,39,155,629,2635,11375,49775,221993, 1000469,4559119,20954301,97007355,452068093, 2117955301,9972403285,47151732371,223801633257, 1065825239793,5091269173915,24386527347883, 117095676603227,563513272181635,2717367767033319, 13128069939371165,63531808704306035] |