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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 107 |
| 5 | 455 |
| 6 | 2012 |
| 7 | 9074 |
| 8 | 41594 |
| 9 | 192924 |
| 10 | 903470 |
| 11 | 4262270 |
| 12 | 20231693 |
| 13 | 96516302 |
| 14 | 462374120 |
| 15 | 2222933809 |
| 16 | 10719593222 |
| 17 | 51828194331 |
| 18 | 251155772898 |
| 19 | 1219515591916 |
| 20 | 5931946148833 |
| 21 | 28899291120181 |
| 22 | 140988919633962 |
| 23 | 688697812814343 |
| 24 | 3367946840981885 |
| 25 | 16487263285545995 |
| 26 | 80786492334172444 |
[1,2,7,26,107,455,2012,9074,41594,192924,903470, 4262270,20231693,96516302,462374120,2222933809, 10719593222,51828194331,251155772898, 1219515591916,5931946148833,28899291120181, 140988919633962,688697812814343,3367946840981885, 16487263285545995,80786492334172444] |