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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 4 |
| 2 | 8 |
| 3 | 18 |
| 4 | 30 |
| 5 | 68 |
| 6 | 128 |
| 7 | 258 |
| 8 | 508 |
| 9 | 1030 |
| 10 | 2052 |
| 11 | 4092 |
| 12 | 8192 |
| 13 | 16400 |
| 14 | 32792 |
| 15 | 65520 |
| 16 | 131058 |
| 17 | 262172 |
| 18 | 524286 |
| 19 | 1048596 |
| 20 | 2097156 |
| 21 | 4194312 |
| 22 | 8388620 |
| 23 | 16777210 |
| 24 | 33554472 |
| 25 | 67108860 |
| 26 | 134217738 |
| 27 | 268435446 |
| 28 | 536870858 |
| 29 | 1073741832 |
| 30 | 2147483616 |
[2,4,8,18,30,68,128,258,508,1030,2052,4092,8192, 16400,32792,65520,131058,262172,524286,1048596, 2097156,4194312,8388620,16777210,33554472, 67108860,134217738,268435446,536870858,1073741832, 2147483616] |