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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 22 |
| 4 | 149 |
| 5 | 1186 |
| 6 | 10807 |
| 7 | 110762 |
| 8 | 1260289 |
| 9 | 15757714 |
| 10 | 214703831 |
| 11 | 3165856882 |
| 12 | 50220944017 |
| 13 | 852735163034 |
| 14 | 15429720661279 |
| 15 | 296365775922106 |
| 16 | 6021825238479617 |
| 17 | 129039801791351842 |
| 18 | 2908148713706872999 |
| 19 | 68758376703814729154 |
| 20 | 1701649010958291917521 |
| 21 | 43990236798804135274282 |
[1,2,4,22,149,1186,10807,110762,1260289,15757714, 214703831,3165856882,50220944017,852735163034, 15429720661279,296365775922106,6021825238479617, 129039801791351842,2908148713706872999, 68758376703814729154,1701649010958291917521, 43990236798804135274282] |