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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 11 |
| 4 | 36 |
| 5 | 125 |
| 6 | 453 |
| 7 | 1643 |
| 8 | 6160 |
| 9 | 23581 |
| 10 | 90833 |
| 11 | 353457 |
| 12 | 1396858 |
| 13 | 5547947 |
| 14 | 22161694 |
| 15 | 89279443 |
| 16 | 361655958 |
| 17 | 1470244295 |
| 18 | 6007452039 |
| 19 | 24661753493 |
| 20 | 101534196798 |
| 21 | 419402648339 |
| 22 | 1738678408812 |
| 23 | 7226334858703 |
| 24 | 30105804655436 |
| 25 | 125763533221311 |
| 26 | 526549835239967 |
| 27 | 2208743593298925 |
| 28 | 9284108802310916 |
[1,1,4,11,36,125,453,1643,6160,23581,90833,353457, 1396858,5547947,22161694,89279443,361655958, 1470244295,6007452039,24661753493,101534196798, 419402648339,1738678408812,7226334858703, 30105804655436,125763533221311,526549835239967, 2208743593298925,9284108802310916] |