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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 12 |
| 3 | 32 |
| 4 | 76 |
| 5 | 176 |
| 6 | 384 |
| 7 | 832 |
| 8 | 1740 |
| 9 | 3632 |
| 10 | 7440 |
| 11 | 15232 |
| 12 | 30848 |
| 13 | 62464 |
| 14 | 125760 |
| 15 | 253184 |
| 16 | 508108 |
| 17 | 1019696 |
| 18 | 2043024 |
| 19 | 4093312 |
| 20 | 8194064 |
| 21 | 16403008 |
| 22 | 32821248 |
| 23 | 65672960 |
| 24 | 131376768 |
| 25 | 262815232 |
| 26 | 525692928 |
| 27 | 1051510784 |
| 28 | 2103147328 |
[1,4,12,32,76,176,384,832,1740,3632,7440,15232, 30848,62464,125760,253184,508108,1019696,2043024, 4093312,8194064,16403008,32821248,65672960, 131376768,262815232,525692928,1051510784, 2103147328] |