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| n | a(n) |
|---|---|
| 1 | 5 |
| 2 | 21 |
| 3 | 28 |
| 4 | 77 |
| 5 | 199 |
| 6 | 454 |
| 7 | 1074 |
| 8 | 2619 |
| 9 | 6216 |
| 10 | 14782 |
| 11 | 35494 |
| 12 | 84850 |
| 13 | 202493 |
| 14 | 484472 |
| 15 | 1158594 |
| 16 | 2768565 |
| 17 | 6619260 |
| 18 | 15826963 |
| 19 | 37833884 |
| 20 | 90447825 |
| 21 | 216242881 |
| 22 | 516964232 |
| 23 | 1235890365 |
| 24 | 2954669861 |
| 25 | 7063719452 |
| 26 | 16887142919 |
| 27 | 40372113631 |
| 28 | 96517561505 |
[5,21,28,77,199,454,1074,2619,6216,14782,35494, 84850,202493,484472,1158594,2768565,6619260, 15826963,37833884,90447825,216242881,516964232, 1235890365,2954669861,7063719452,16887142919, 40372113631,96517561505] |