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A075756
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Number of hierarchies of hierarchies of hierarchies on n points.
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1
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1, 1, 6, 52, 588, 8174, 134537, 2554647, 54909468, 1316675221, 34820961457, 1006230148609, 31529224324159, 1064355502971193, 38497326001639439, 1484865225798412485, 60822449267067095601, 2636248249383130776940, 120520100503562054999860, 5794815395039941996204424
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OFFSET
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0,3
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LINKS
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FORMULA
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E.g.f.: exp(f(x)-1) where f(x) = e.g.f. for A075744.
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MATHEMATICA
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m = 20;
f[x_] = E^(-1 + E^(-1 + 1/(2 - E^x)));
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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