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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 6 |
| 3 | 15 |
| 4 | 37 |
| 5 | 80 |
| 6 | 183 |
| 7 | 428 |
| 8 | 893 |
| 9 | 1944 |
| 10 | 4223 |
| 11 | 8691 |
| 12 | 18128 |
| 13 | 37529 |
| 14 | 75738 |
| 15 | 153460 |
| 16 | 308829 |
| 17 | 612006 |
| 18 | 1211097 |
| 19 | 2386016 |
| 20 | 4648229 |
| 21 | 9042678 |
| 22 | 17528035 |
| 23 | 33645928 |
| 24 | 64508161 |
| 25 | 123178953 |
| 26 | 233709589 |
| 27 | 442583046 |
| 28 | 834923483 |
| 29 | 1567271495 |
| 30 | 2935406996 |
| 31 | 5481361193 |
| 32 | 10191781534 |
[1,3,6,15,37,80,183,428,893,1944,4223,8691,18128, 37529,75738,153460,308829,612006,1211097,2386016, 4648229,9042678,17528035,33645928,64508161, 123178953,233709589,442583046,834923483, 1567271495,2935406996,5481361193,10191781534] |