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| n | a(n) |
|---|---|
| 15 | 1 |
| 16 | 6 |
| 17 | 18 |
| 18 | 57 |
| 19 | 165 |
| 20 | 460 |
| 21 | 1242 |
| 22 | 3295 |
| 23 | 8589 |
| 24 | 22169 |
| 25 | 56675 |
| 26 | 143941 |
| 27 | 363527 |
| 28 | 914253 |
| 29 | 2291088 |
| 30 | 5725579 |
| 31 | 14275461 |
| 32 | 35526939 |
| 33 | 88279211 |
| 34 | 219088566 |
| 35 | 543169235 |
| 36 | 1345516437 |
| 37 | 3330785029 |
| 38 | 8240718421 |
| 39 | 20379364252 |
| 40 | 50380569630 |
| 41 | 124513186628 |
| 42 | 307663311638 |
| 43 | 760095010218 |
[1,6,18,57,165,460,1242,3295,8589,22169,56675, 143941,363527,914253,2291088,5725579,14275461, 35526939,88279211,219088566,543169235,1345516437, 3330785029,8240718421,20379364252,50380569630, 124513186628,307663311638,760095010218] |