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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 101 |
| 5 | 402 |
| 6 | 1625 |
| 7 | 6638 |
| 8 | 27319 |
| 9 | 113054 |
| 10 | 469811 |
| 11 | 1958706 |
| 12 | 8187063 |
| 13 | 34290934 |
| 14 | 143864999 |
| 15 | 604402050 |
| 16 | 2542083509 |
| 17 | 10702020746 |
| 18 | 45090876913 |
| 19 | 190110250998 |
| 20 | 801997354525 |
| 21 | 3384971428258 |
| 22 | 14292950533517 |
| 23 | 60373808435046 |
| 24 | 255102065046401 |
| 25 | 1078202260326002 |
[1,2,7,26,101,402,1625,6638,27319,113054,469811, 1958706,8187063,34290934,143864999,604402050, 2542083509,10702020746,45090876913,190110250998, 801997354525,3384971428258,14292950533517, 60373808435046,255102065046401,1078202260326002] |