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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 34 |
| 3 | 260 |
| 4 | 2056 |
| 5 | 16400 |
| 6 | 131104 |
| 7 | 1048640 |
| 8 | 8388736 |
| 9 | 67109120 |
| 10 | 536871424 |
| 11 | 4294968320 |
| 12 | 34359740416 |
| 13 | 274877911040 |
| 14 | 2199023263744 |
| 15 | 17592186060800 |
| 16 | 140737488388096 |
| 17 | 1125899906908160 |
| 18 | 9007199254872064 |
| 19 | 72057594038190080 |
| 20 | 576460752303947776 |
| 21 | 4611686018428436480 |
[1,5,34,260,2056,16400,131104,1048640,8388736, 67109120,536871424,4294968320,34359740416, 274877911040,2199023263744,17592186060800, 140737488388096,1125899906908160,9007199254872064, 72057594038190080,576460752303947776, 4611686018428436480] |