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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 20 |
| 4 | 90 |
| 5 | 272 |
| 6 | 650 |
| 7 | 1332 |
| 8 | 4160 |
| 9 | 6642 |
| 10 | 10100 |
| 11 | 14762 |
| 12 | 20880 |
| 13 | 28730 |
| 14 | 38612 |
| 15 | 50850 |
| 16 | 65792 |
| 17 | 83810 |
| 18 | 130682 |
| 19 | 160400 |
| 20 | 194922 |
| 21 | 234740 |
| 22 | 280370 |
| 23 | 332352 |
| 24 | 391250 |
| 25 | 457652 |
| 26 | 532170 |
| 27 | 615440 |
| 28 | 708122 |
| 29 | 810900 |
| 30 | 924482 |
| 31 | 1187010 |
| 32 | 1337492 |
| 33 | 1501850 |
| 34 | 1680912 |
| 35 | 1875530 |
| 36 | 2314962 |
| 37 | 2561600 |
[1,2,20,90,272,650,1332,4160,6642,10100,14762, 20880,28730,38612,50850,65792,83810,130682,160400, 194922,234740,280370,332352,391250,457652,532170, 615440,708122,810900,924482,1187010,1337492, 1501850,1680912,1875530,2314962,2561600] |