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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 16 |
| 3 | 61 |
| 4 | 233 |
| 5 | 896 |
| 6 | 3444 |
| 7 | 13225 |
| 8 | 50789 |
| 9 | 195076 |
| 10 | 749256 |
| 11 | 2877717 |
| 12 | 11052673 |
| 13 | 42450984 |
| 14 | 163045180 |
| 15 | 626221537 |
| 16 | 2405182717 |
| 17 | 9237791852 |
| 18 | 35480380112 |
| 19 | 136272540429 |
| 20 | 523393640665 |
| 21 | 2010242874320 |
| 22 | 7720912327300 |
| 23 | 29654370583449 |
[4,16,61,233,896,3444,13225,50789,195076,749256, 2877717,11052673,42450984,163045180,626221537, 2405182717,9237791852,35480380112,136272540429, 523393640665,2010242874320,7720912327300, 29654370583449] |