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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 11 |
| 6 | 31 |
| 7 | 91 |
| 8 | 250 |
| 9 | 690 |
| 10 | 1863 |
| 11 | 5017 |
| 12 | 13389 |
| 13 | 35621 |
| 14 | 94354 |
| 15 | 249352 |
| 16 | 657421 |
| 17 | 1730685 |
| 18 | 4550031 |
| 19 | 11950963 |
| 20 | 31365810 |
| 21 | 82274126 |
| 22 | 215711947 |
| 23 | 565376593 |
| 24 | 1481448697 |
| 25 | 3881041065 |
| 26 | 10165822434 |
| 27 | 26624745964 |
| 28 | 69725071281 |
| 29 | 182583838181 |
| 30 | 478093234315 |
| 31 | 1251829592839 |
[1,3,11,31,91,250,690,1863,5017,13389,35621,94354, 249352,657421,1730685,4550031,11950963,31365810, 82274126,215711947,565376593,1481448697, 3881041065,10165822434,26624745964,69725071281, 182583838181,478093234315,1251829592839] |