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| n | a(n) |
|---|---|
| 4 | 70 |
| 5 | 756 |
| 6 | 4410 |
| 7 | 18480 |
| 8 | 62370 |
| 9 | 180180 |
| 10 | 462462 |
| 11 | 1081080 |
| 12 | 2342340 |
| 13 | 4764760 |
| 14 | 9189180 |
| 15 | 16930368 |
| 16 | 29980860 |
| 17 | 51279480 |
| 18 | 85058820 |
| 19 | 137287920 |
| 20 | 216228474 |
| 21 | 333125100 |
| 22 | 503052550 |
| 23 | 745945200 |
| 24 | 1087836750 |
| 25 | 1562340780 |
| 26 | 2212405650 |
| 27 | 3092380200 |
| 28 | 4270429800 |
| 29 | 5831345520 |
| 30 | 7879792536 |
[70,756,4410,18480,62370,180180,462462,1081080, 2342340,4764760,9189180,16930368,29980860, 51279480,85058820,137287920,216228474,333125100, 503052550,745945200,1087836750,1562340780, 2212405650,3092380200,4270429800,5831345520, 7879792536] |