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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 10 |
| 4 | 25 |
| 5 | 58 |
| 6 | 130 |
| 7 | 286 |
| 8 | 620 |
| 9 | 1329 |
| 10 | 2827 |
| 11 | 5977 |
| 12 | 12559 |
| 13 | 26227 |
| 14 | 54493 |
| 15 | 112849 |
| 16 | 233272 |
| 17 | 481616 |
| 18 | 992955 |
| 19 | 2043238 |
| 20 | 4194649 |
| 21 | 8591014 |
| 22 | 17559133 |
| 23 | 35833948 |
| 24 | 73054885 |
| 25 | 148849186 |
| 26 | 303171755 |
| 27 | 617306563 |
| 28 | 1256452642 |
| 29 | 2555937826 |
[1,4,10,25,58,130,286,620,1329,2827,5977,12559, 26227,54493,112849,233272,481616,992955,2043238, 4194649,8591014,17559133,35833948,73054885, 148849186,303171755,617306563,1256452642, 2555937826] |