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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 4 |
| 3 | 16 |
| 4 | 43 |
| 5 | 122 |
| 6 | 345 |
| 7 | 979 |
| 8 | 2791 |
| 9 | 7936 |
| 10 | 22540 |
| 11 | 64031 |
| 12 | 181974 |
| 13 | 517221 |
| 14 | 1469927 |
| 15 | 4177203 |
| 16 | 11870804 |
| 17 | 33735384 |
| 18 | 95872371 |
| 19 | 272457370 |
| 20 | 774287065 |
| 21 | 2200420843 |
| 22 | 6253312335 |
| 23 | 17771112208 |
| 24 | 50503204860 |
| 25 | 143523553079 |
| 26 | 407875327102 |
[4,4,16,43,122,345,979,2791,7936,22540,64031, 181974,517221,1469927,4177203,11870804,33735384, 95872371,272457370,774287065,2200420843, 6253312335,17771112208,50503204860,143523553079, 407875327102] |