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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 32 |
| 4 | 90 |
| 5 | 231 |
| 6 | 576 |
| 7 | 1363 |
| 8 | 3141 |
| 9 | 7003 |
| 10 | 15261 |
| 11 | 32468 |
| 12 | 67788 |
| 13 | 138892 |
| 14 | 280103 |
| 15 | 556302 |
| 16 | 1089991 |
| 17 | 2108332 |
| 18 | 4030649 |
| 19 | 7620671 |
| 20 | 14261450 |
| 21 | 26431346 |
| 22 | 48544170 |
| 23 | 88393064 |
| 24 | 159654022 |
| 25 | 286149924 |
| 26 | 509137464 |
| 27 | 899603036 |
| 28 | 1579014769 |
[1,3,11,32,90,231,576,1363,3141,7003,15261,32468, 67788,138892,280103,556302,1089991,2108332, 4030649,7620671,14261450,26431346,48544170, 88393064,159654022,286149924,509137464,899603036, 1579014769] |