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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 21 |
| 3 | 151 |
| 4 | 1257 |
| 5 | 12651 |
| 6 | 151933 |
| 7 | 2127231 |
| 8 | 34035921 |
| 9 | 612646867 |
| 10 | 12252937701 |
| 11 | 269564629863 |
| 12 | 6469551117241 |
| 13 | 168208329048891 |
| 14 | 4709833213369677 |
| 15 | 141294996401091151 |
| 16 | 4521439884834917793 |
| 17 | 153728956084387206051 |
| 18 | 5534242419037939419061 |
| 19 | 210301211923441697925687 |
[1,3,21,151,1257,12651,151933,2127231,34035921, 612646867,12252937701,269564629863,6469551117241, 168208329048891,4709833213369677, 141294996401091151,4521439884834917793, 153728956084387206051,5534242419037939419061, 210301211923441697925687] |