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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 22 |
| 3 | 110 |
| 4 | 453 |
| 5 | 1482 |
| 6 | 4083 |
| 7 | 9926 |
| 8 | 21959 |
| 9 | 45122 |
| 10 | 87347 |
| 11 | 160922 |
| 12 | 284310 |
| 13 | 484528 |
| 14 | 800206 |
| 15 | 1285462 |
| 16 | 2014746 |
| 17 | 3088824 |
| 18 | 4642092 |
| 19 | 6851430 |
| 20 | 9946827 |
| 21 | 14224030 |
| 22 | 20059493 |
| 23 | 27927926 |
| 24 | 38422769 |
| 25 | 52279942 |
| 26 | 70405249 |
| 27 | 93905842 |
| 28 | 124126180 |
[4,22,110,453,1482,4083,9926,21959,45122,87347, 160922,284310,484528,800206,1285462,2014746, 3088824,4642092,6851430,9946827,14224030,20059493, 27927926,38422769,52279942,70405249,93905842, 124126180] |