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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 7 |
| 4 | 20 |
| 5 | 21 |
| 6 | 88 |
| 7 | 71 |
| 8 | 296 |
| 9 | 373 |
| 10 | 1084 |
| 11 | 1035 |
| 12 | 5084 |
| 13 | 4109 |
| 14 | 16496 |
| 15 | 20787 |
| 16 | 67728 |
| 17 | 65553 |
| 18 | 286516 |
| 19 | 262163 |
| 20 | 1070180 |
| 21 | 1189937 |
| 22 | 4194568 |
| 23 | 4194327 |
| 24 | 17760824 |
| 25 | 16827241 |
| 26 | 67109228 |
| 27 | 72150655 |
| 28 | 269503660 |
| 29 | 268435485 |
| 30 | 1104603808 |
| 31 | 1073741855 |
| 32 | 4303389216 |
| 33 | 4476371181 |
[1,4,7,20,21,88,71,296,373,1084,1035,5084,4109, 16496,20787,67728,65553,286516,262163,1070180, 1189937,4194568,4194327,17760824,16827241, 67109228,72150655,269503660,268435485,1104603808, 1073741855,4303389216,4476371181] |