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A331114
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Number of rooted trees with 2-colored non-root nodes with an n nodes of each color.
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3
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1, 3, 37, 596, 11513, 245356, 5597060, 133950215, 3323281496, 84787933926, 2212123329500, 58779046239904, 1585796125188065, 43337540217740908, 1197492197496481744, 33406620056723507124, 939775084670916268134, 26632926871927867655261, 759732892913483065912296
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OFFSET
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0,2
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COMMENTS
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The total number of nodes including the root is 2n + 1.
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LINKS
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FORMULA
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EXAMPLE
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a(1) = 3 because there are three trees with one root node and one additional node of each color:
1 -- o -- 2,
o -- 1 -- 2,
o -- 2 -- 1.
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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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