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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 6 |
| 3 | 12 |
| 4 | 25 |
| 5 | 53 |
| 6 | 116 |
| 7 | 259 |
| 8 | 594 |
| 9 | 1389 |
| 10 | 3323 |
| 11 | 8095 |
| 12 | 20113 |
| 13 | 50814 |
| 14 | 130632 |
| 15 | 341034 |
| 16 | 904331 |
| 17 | 2432412 |
| 18 | 6636111 |
| 19 | 18345401 |
| 20 | 51381503 |
| 21 | 145690844 |
| 22 | 418123477 |
| 23 | 1213876444 |
| 24 | 3563936878 |
| 25 | 10577119368 |
| 26 | 31722511379 |
| 27 | 96106797203 |
| 28 | 294036698701 |
[3,6,12,25,53,116,259,594,1389,3323,8095,20113, 50814,130632,341034,904331,2432412,6636111, 18345401,51381503,145690844,418123477,1213876444, 3563936878,10577119368,31722511379,96106797203, 294036698701] |