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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 5 |
| 3 | 38 |
| 4 | 309 |
| 5 | 2012 |
| 6 | 12160 |
| 7 | 70722 |
| 8 | 395223 |
| 9 | 2150350 |
| 10 | 11454117 |
| 11 | 59948615 |
| 12 | 309270883 |
| 13 | 1576188831 |
| 14 | 7949681739 |
| 15 | 39734943909 |
| 16 | 197045928939 |
| 17 | 970369807931 |
| 18 | 4749163345697 |
| 19 | 23114719065210 |
| 20 | 111941467863241 |
| 21 | 539671083601641 |
[0,5,38,309,2012,12160,70722,395223,2150350, 11454117,59948615,309270883,1576188831,7949681739, 39734943909,197045928939,970369807931, 4749163345697,23114719065210,111941467863241, 539671083601641] |