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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 8 |
| 4 | 24 |
| 5 | 56 |
| 6 | 152 |
| 7 | 376 |
| 8 | 984 |
| 9 | 2488 |
| 10 | 6424 |
| 11 | 16376 |
| 12 | 42072 |
| 13 | 107576 |
| 14 | 275864 |
| 15 | 706168 |
| 16 | 1809624 |
| 17 | 4634296 |
| 18 | 11872792 |
| 19 | 30409976 |
| 20 | 77901144 |
| 21 | 199541048 |
| 22 | 511145624 |
| 23 | 1309309816 |
| 24 | 3353892312 |
| 25 | 8591131576 |
| 26 | 22006700824 |
| 27 | 56371227128 |
| 28 | 144398030424 |
| 29 | 369882938936 |
| 30 | 947475060632 |
| 31 | 2427006816376 |
[1,4,8,24,56,152,376,984,2488,6424,16376,42072, 107576,275864,706168,1809624,4634296,11872792, 30409976,77901144,199541048,511145624,1309309816, 3353892312,8591131576,22006700824,56371227128, 144398030424,369882938936,947475060632, 2427006816376] |