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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 5 |
| 5 | 31 |
| 6 | 82 |
| 7 | 344 |
| 8 | 1661 |
| 9 | 7942 |
| 10 | 38721 |
| 11 | 228680 |
| 12 | 1377026 |
| 13 | 8529756 |
| 14 | 56756260 |
| 15 | 402300799 |
| 16 | 2960135917 |
| 17 | 22692746719 |
| 18 | 181667760724 |
| 19 | 1516381486766 |
| 20 | 13135566948285 |
| 21 | 117868982320877 |
| 22 | 1093961278908818 |
| 23 | 10492653292100919 |
| 24 | 103880022098900234 |
| 25 | 1059925027073166856 |
[1,1,4,5,31,82,344,1661,7942,38721,228680,1377026, 8529756,56756260,402300799,2960135917,22692746719, 181667760724,1516381486766,13135566948285, 117868982320877,1093961278908818, 10492653292100919,103880022098900234, 1059925027073166856] |