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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 18 |
| 4 | 2593 |
| 5 | 39979 |
| 6 | 281514 |
| 7 | 1301950 |
| 8 | 4618099 |
| 9 | 13628193 |
| 10 | 35115244 |
| 11 | 81502564 |
| 12 | 174076485 |
| 13 | 347418199 |
| 14 | 655313518 |
| 15 | 1178436234 |
| 16 | 2034127639 |
| 17 | 3388621645 |
| 18 | 5472091824 |
| 19 | 8596923568 |
| 20 | 13179641449 |
| 21 | 19766948739 |
| 22 | 29066362930 |
| 23 | 41981957974 |
| 24 | 59655750843 |
| 25 | 83515296889 |
[0,0,0,18,2593,39979,281514,1301950,4618099, 13628193,35115244,81502564,174076485,347418199, 655313518,1178436234,2034127639,3388621645, 5472091824,8596923568,13179641449,19766948739, 29066362930,41981957974,59655750843,83515296889] |