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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 33 |
| 4 | 153 |
| 5 | 656 |
| 6 | 3085 |
| 7 | 13956 |
| 8 | 66521 |
| 9 | 308589 |
| 10 | 1484578 |
| 11 | 6994672 |
| 12 | 33852585 |
| 13 | 161210627 |
| 14 | 783499644 |
| 15 | 3759872734 |
| 16 | 18331111253 |
| 17 | 88471786249 |
| 18 | 432412838581 |
| 19 | 2096144793439 |
| 20 | 10265712110735 |
| 21 | 49936363483570 |
| 22 | 244967702066380 |
| 23 | 1194958562465534 |
| 24 | 5870227136671303 |
| 25 | 28701248466875263 |
| 26 | 141164173819529544 |
[1,2,9,33,153,656,3085,13956,66521,308589,1484578, 6994672,33852585,161210627,783499644,3759872734, 18331111253,88471786249,432412838581, 2096144793439,10265712110735,49936363483570, 244967702066380,1194958562465534,5870227136671303, 28701248466875263,141164173819529544] |