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| n | a(n) |
|---|---|
| 1 | 64 |
| 2 | 308 |
| 3 | 2116 |
| 4 | 16892 |
| 5 | 143224 |
| 6 | 1250228 |
| 7 | 11091536 |
| 8 | 99371772 |
| 9 | 895878604 |
| 10 | 8109607248 |
| 11 | 73605150496 |
| 12 | 669235388612 |
| 13 | 6091889767144 |
| 14 | 55495316073288 |
| 15 | 505799972171296 |
| 16 | 4611529143198652 |
| 17 | 42053844507644124 |
| 18 | 383555932615158068 |
| 19 | 3498586905231628036 |
| 20 | 31914171636394303392 |
[64,308,2116,16892,143224,1250228,11091536, 99371772,895878604,8109607248,73605150496, 669235388612,6091889767144,55495316073288, 505799972171296,4611529143198652, 42053844507644124,383555932615158068, 3498586905231628036,31914171636394303392] |