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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 10 |
| 3 | 20 |
| 4 | 130 |
| 5 | 396 |
| 6 | 2842 |
| 7 | 4420 |
| 8 | 38610 |
| 9 | 124220 |
| 10 | 684490 |
| 11 | 1385044 |
| 12 | 8891330 |
| 13 | 26281036 |
| 14 | 192525274 |
| 15 | 269101060 |
| 16 | 2454365330 |
| 17 | 8588410876 |
| 18 | 43860512138 |
| 19 | 89059958420 |
| 20 | 551714970626 |
| 21 | 1663794165260 |
| 22 | 12235920695450 |
| 23 | 19683098342340 |
| 24 | 164315052318034 |
| 25 | 538162708968636 |
| 26 | 2894532467106378 |
| 27 | 6192136868790228 |
| 28 | 37503903254935874 |
| 29 | 114926395086966988 |
| 30 | 814341599153559130 |
[0,0,10,20,130,396,2842,4420,38610,124220,684490, 1385044,8891330,26281036,192525274,269101060, 2454365330,8588410876,43860512138,89059958420, 551714970626,1663794165260,12235920695450, 19683098342340,164315052318034,538162708968636, 2894532467106378,6192136868790228, 37503903254935874,114926395086966988, 814341599153559130] |