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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 12 |
| 3 | 34 |
| 4 | 96 |
| 5 | 262 |
| 6 | 706 |
| 7 | 1866 |
| 8 | 4876 |
| 9 | 12590 |
| 10 | 32220 |
| 11 | 81780 |
| 12 | 206182 |
| 13 | 516682 |
| 14 | 1288100 |
| 15 | 3196414 |
| 16 | 7899664 |
| 17 | 19452002 |
| 18 | 47741832 |
| 19 | 116827972 |
| 20 | 285121530 |
| 21 | 694145540 |
| 22 | 1686165640 |
| 23 | 4087501476 |
| 24 | 9889956114 |
| 25 | 23887544730 |
| 26 | 57602999360 |
| 27 | 138696210062 |
| 28 | 333483756402 |
| 29 | 800784138674 |
| 30 | 1920539773188 |
| 31 | 4600776445384 |
| 32 | 11009534409116 |
| 33 | 26318680827474 |
| 34 | 62855267076802 |
| 35 | 149976974496002 |
| 36 | 357547693790338 |
| 37 | 851705230512838 |
| 38 | 2027255882196068 |
[4,12,34,96,262,706,1866,4876,12590,32220,81780, 206182,516682,1288100,3196414,7899664,19452002, 47741832,116827972,285121530,694145540,1686165640, 4087501476,9889956114,23887544730,57602999360, 138696210062,333483756402,800784138674, 1920539773188,4600776445384,11009534409116, 26318680827474,62855267076802,149976974496002, 357547693790338,851705230512838,2027255882196068] |