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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 7 |
| 3 | 16 |
| 4 | 35 |
| 5 | 78 |
| 6 | 171 |
| 7 | 383 |
| 8 | 849 |
| 9 | 1919 |
| 10 | 4301 |
| 11 | 9807 |
| 12 | 22193 |
| 13 | 50993 |
| 14 | 116349 |
| 15 | 269094 |
| 16 | 618277 |
| 17 | 1437916 |
| 18 | 3323277 |
| 19 | 7764996 |
| 20 | 18035275 |
| 21 | 42304904 |
| 22 | 98668223 |
| 23 | 232198092 |
| 24 | 543453693 |
| 25 | 1282401208 |
| 26 | 3010275001 |
| 27 | 7119589730 |
| 28 | 16753996391 |
[1,3,7,16,35,78,171,383,849,1919,4301,9807,22193, 50993,116349,269094,618277,1437916,3323277, 7764996,18035275,42304904,98668223,232198092, 543453693,1282401208,3010275001,7119589730, 16753996391] |