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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 31 |
| 4 | 145 |
| 5 | 587 |
| 6 | 2791 |
| 7 | 12106 |
| 8 | 58124 |
| 9 | 261744 |
| 10 | 1264717 |
| 11 | 5828785 |
| 12 | 28292206 |
| 13 | 132437321 |
| 14 | 645033524 |
| 15 | 3053061983 |
| 16 | 14909656701 |
| 17 | 71152742334 |
| 18 | 348223759551 |
| 19 | 1672326960269 |
| 20 | 8198958472117 |
| 21 | 39571030467943 |
| 22 | 194295312406676 |
| 23 | 941486927645661 |
| 24 | 4628620226911394 |
| 25 | 22502035601784115 |
| 26 | 110748086623000399 |
[1,2,9,31,145,587,2791,12106,58124,261744,1264717, 5828785,28292206,132437321,645033524,3053061983, 14909656701,71152742334,348223759551, 1672326960269,8198958472117,39571030467943, 194295312406676,941486927645661,4628620226911394, 22502035601784115,110748086623000399] |