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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 4 |
| 2 | 20 |
| 3 | 60 |
| 4 | 140 |
| 5 | 280 |
| 6 | 504 |
| 7 | 840 |
| 8 | 1320 |
| 9 | 1980 |
| 10 | 2860 |
| 11 | 4004 |
| 12 | 5460 |
| 13 | 7280 |
| 14 | 9520 |
| 15 | 12240 |
| 16 | 15504 |
| 17 | 19380 |
| 18 | 23940 |
| 19 | 29260 |
| 20 | 35420 |
| 21 | 42504 |
| 22 | 50600 |
| 23 | 59800 |
| 24 | 70200 |
| 25 | 81900 |
| 26 | 95004 |
| 27 | 109620 |
| 28 | 125860 |
| 29 | 143840 |
| 30 | 163680 |
| 31 | 185504 |
| 32 | 209440 |
[0,4,20,60,140,280,504,840,1320,1980,2860,4004, 5460,7280,9520,12240,15504,19380,23940,29260, 35420,42504,50600,59800,70200,81900,95004,109620, 125860,143840,163680,185504,209440] |