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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 12 |
| 4 | 35 |
| 5 | 75 |
| 6 | 181 |
| 7 | 490 |
| 8 | 1061 |
| 9 | 2707 |
| 10 | 6459 |
| 11 | 15932 |
| 12 | 40127 |
| 13 | 100362 |
| 14 | 251711 |
| 15 | 637236 |
| 16 | 1617181 |
| 17 | 4124444 |
| 18 | 10553419 |
| 19 | 27066987 |
| 20 | 69709706 |
| 21 | 179992917 |
| 22 | 465769804 |
| 23 | 1208198534 |
| 24 | 3140421726 |
| 25 | 8179002096 |
| 26 | 21338685437 |
| 27 | 55762149044 |
| 28 | 145935689364 |
| 29 | 382465573484 |
| 30 | 1003652347334 |
[1,1,12,35,75,181,490,1061,2707,6459,15932,40127, 100362,251711,637236,1617181,4124444,10553419, 27066987,69709706,179992917,465769804,1208198534, 3140421726,8179002096,21338685437,55762149044, 145935689364,382465573484,1003652347334] |