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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 54 |
| 5 | 218 |
| 6 | 790 |
| 7 | 2614 |
| 8 | 7989 |
| 9 | 22756 |
| 10 | 60950 |
| 11 | 154631 |
| 12 | 373880 |
| 13 | 866019 |
| 14 | 1930121 |
| 15 | 4154593 |
| 16 | 8664718 |
| 17 | 17557769 |
| 18 | 34651632 |
| 19 | 66747915 |
| 20 | 125725045 |
| 21 | 231949573 |
| 22 | 419750808 |
| 23 | 746081780 |
| 24 | 1304039046 |
| 25 | 2243705012 |
| 26 | 3803904385 |
| 27 | 6360060015 |
| 28 | 10495565911 |
| 29 | 17107197521 |
[1,3,12,54,218,790,2614,7989,22756,60950,154631, 373880,866019,1930121,4154593,8664718,17557769, 34651632,66747915,125725045,231949573,419750808, 746081780,1304039046,2243705012,3803904385, 6360060015,10495565911,17107197521] |