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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 28 |
| 4 | 133 |
| 5 | 651 |
| 6 | 3206 |
| 7 | 15771 |
| 8 | 77519 |
| 9 | 380989 |
| 10 | 1872556 |
| 11 | 9203761 |
| 12 | 45237262 |
| 13 | 222344668 |
| 14 | 1092840924 |
| 15 | 5371396171 |
| 16 | 26400821252 |
| 17 | 129762048116 |
| 18 | 637790353236 |
| 19 | 3134788177277 |
| 20 | 15407722718291 |
| 21 | 75730131016730 |
| 22 | 372219363549007 |
| 23 | 1829486529878612 |
| 24 | 8992065676243395 |
[1,6,28,133,651,3206,15771,77519,380989,1872556, 9203761,45237262,222344668,1092840924,5371396171, 26400821252,129762048116,637790353236, 3134788177277,15407722718291,75730131016730, 372219363549007,1829486529878612,8992065676243395] |