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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 4 |
| 3 | 20 |
| 4 | 20 |
| 5 | 36 |
| 6 | 100 |
| 7 | 116 |
| 8 | 180 |
| 9 | 260 |
| 10 | 580 |
| 11 | 660 |
| 12 | 1044 |
| 13 | 1380 |
| 14 | 2020 |
| 15 | 3444 |
| 16 | 4340 |
| 17 | 6020 |
| 18 | 8260 |
| 19 | 11220 |
| 20 | 14740 |
| 21 | 23140 |
| 22 | 28196 |
| 23 | 38900 |
| 24 | 50420 |
| 25 | 67780 |
| 26 | 85956 |
| 27 | 114900 |
| 28 | 157140 |
| 29 | 197860 |
| 30 | 257060 |
| 31 | 331060 |
| 32 | 423540 |
| 33 | 540100 |
| 34 | 687620 |
| 35 | 864084 |
| 36 | 1145300 |
| 37 | 1406500 |
| 38 | 1789860 |
| 39 | 2231860 |
[1,4,4,20,20,36,100,116,180,260,580,660,1044,1380, 2020,3444,4340,6020,8260,11220,14740,23140,28196, 38900,50420,67780,85956,114900,157140,197860, 257060,331060,423540,540100,687620,864084,1145300, 1406500,1789860,2231860] |