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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 28 |
| 4 | 120 |
| 5 | 496 |
| 6 | 2016 |
| 7 | 8128 |
| 8 | 32640 |
| 9 | 130816 |
| 10 | 523776 |
| 11 | 2096128 |
| 12 | 8386560 |
| 13 | 33550336 |
| 14 | 134209536 |
| 15 | 536854528 |
| 16 | 2147450880 |
| 17 | 8589869056 |
| 18 | 34359607296 |
| 19 | 137438691328 |
| 20 | 549755289600 |
| 21 | 2199022206976 |
| 22 | 8796090925056 |
| 23 | 35184367894528 |
| 24 | 140737479966720 |
| 25 | 562949936644096 |
[0,1,6,28,120,496,2016,8128,32640,130816,523776, 2096128,8386560,33550336,134209536,536854528, 2147450880,8589869056,34359607296,137438691328, 549755289600,2199022206976,8796090925056, 35184367894528,140737479966720,562949936644096] |