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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 45 |
| 3 | 900 |
| 4 | 19305 |
| 5 | 437076 |
| 6 | 10254681 |
| 7 | 246553875 |
| 8 | 6035226975 |
| 9 | 149777902710 |
| 10 | 3757716928053 |
| 11 | 95110270281675 |
| 12 | 2424907723685985 |
| 13 | 62204709603345075 |
| 14 | 1604054030028748830 |
| 15 | 41549974064592136020 |
| 16 | 1080505644116115671622 |
| 17 | 28195636842752845510215 |
| 18 | 738014045325584817820275 |
[1,3,45,900,19305,437076,10254681,246553875, 6035226975,149777902710,3757716928053, 95110270281675,2424907723685985,62204709603345075, 1604054030028748830,41549974064592136020, 1080505644116115671622,28195636842752845510215, 738014045325584817820275] |