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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 16 |
| 5 | 56 |
| 6 | 272 |
| 7 | 1184 |
| 8 | 4608 |
| 9 | 17536 |
| 10 | 65792 |
| 11 | 254464 |
| 12 | 1017856 |
| 13 | 4130816 |
| 14 | 16781312 |
| 15 | 67641344 |
| 16 | 270532608 |
| 17 | 1077968896 |
| 18 | 4295032832 |
| 19 | 17146445824 |
| 20 | 68585783296 |
| 21 | 274609995776 |
| 22 | 1099512676352 |
| 23 | 4400196091904 |
| 24 | 17600775979008 |
| 25 | 70385932435456 |
| 26 | 281474993487872 |
[1,2,4,16,56,272,1184,4608,17536,65792,254464, 1017856,4130816,16781312,67641344,270532608, 1077968896,4295032832,17146445824,68585783296, 274609995776,1099512676352,4400196091904, 17600775979008,70385932435456,281474993487872] |