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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 25 |
| 4 | 92 |
| 5 | 345 |
| 6 | 1311 |
| 7 | 5030 |
| 8 | 19439 |
| 9 | 75545 |
| 10 | 294888 |
| 11 | 1155205 |
| 12 | 4538745 |
| 13 | 17876250 |
| 14 | 70553179 |
| 15 | 278949705 |
| 16 | 1104585634 |
| 17 | 4379770585 |
| 18 | 17386456213 |
| 19 | 69090680674 |
| 20 | 274806384941 |
| 21 | 1093933313537 |
| 22 | 4357881016922 |
| 23 | 17371974200097 |
| 24 | 69292334180593 |
| 25 | 276541159696582 |
[1,2,7,25,92,345,1311,5030,19439,75545,294888, 1155205,4538745,17876250,70553179,278949705, 1104585634,4379770585,17386456213,69090680674, 274806384941,1093933313537,4357881016922, 17371974200097,69292334180593,276541159696582] |