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A331114 Number of rooted trees with 2-colored non-root nodes with an n nodes of each color. 3
1, 3, 37, 596, 11513, 245356, 5597060, 133950215, 3323281496, 84787933926, 2212123329500, 58779046239904, 1585796125188065, 43337540217740908, 1197492197496481744, 33406620056723507124, 939775084670916268134, 26632926871927867655261, 759732892913483065912296 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
The total number of nodes including the root is 2n + 1.
LINKS
FORMULA
a(n) = A304489(2*n+1, n).
EXAMPLE
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.
CROSSREFS
Sequence in context: A216696 A362724 A333385 * A245265 A362672 A143639
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Jan 09 2020
STATUS
approved

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Last modified March 29 03:51 EDT 2024. Contains 371264 sequences. (Running on oeis4.)