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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 7 |
| 3 | 15 |
| 4 | 33 |
| 5 | 75 |
| 6 | 171 |
| 7 | 387 |
| 8 | 873 |
| 9 | 1971 |
| 10 | 4455 |
| 11 | 10071 |
| 12 | 22761 |
| 13 | 51435 |
| 14 | 116235 |
| 15 | 262683 |
| 16 | 593649 |
| 17 | 1341603 |
| 18 | 3031911 |
| 19 | 6851871 |
| 20 | 15484689 |
| 21 | 34994187 |
| 22 | 79084107 |
| 23 | 178723827 |
| 24 | 403901721 |
| 25 | 912786003 |
| 26 | 2062824327 |
| 27 | 4661820135 |
| 28 | 10535345433 |
| 29 | 23809048875 |
| 30 | 53806570731 |
| 31 | 121598601867 |
[1,3,7,15,33,75,171,387,873,1971,4455,10071,22761, 51435,116235,262683,593649,1341603,3031911, 6851871,15484689,34994187,79084107,178723827, 403901721,912786003,2062824327,4661820135, 10535345433,23809048875,53806570731,121598601867] |