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A346779 Number of Halin graphs on n nodes. 2
0, 0, 0, 1, 1, 2, 2, 4, 6, 13, 22, 50, 106, 252, 589, 1475, 3669, 9435, 24345, 63837, 168234, 447562, 1196390, 3218221 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
LINKS
Eric Weisstein's World of Mathematics, Halin Graph
Peter J. Taylor, Python program
EXAMPLE
a(4) = 1 (K_4)
a(5) = 1 (W_5)
a(6) = 2 (3-prism graph, W_6)
a(7) = 2 (W_7 and one other)
a(8) = 4 (W_8 and 3 others)
PROG
(Python) # See Taylor link
CROSSREFS
Sequence in context: A268175 A363578 A209025 * A153955 A074028 A181926
KEYWORD
nonn,more
AUTHOR
Eric W. Weisstein, Aug 03 2021
EXTENSIONS
a(13) from Eric W. Weisstein, Aug 16 2021
a(14) from Eric W. Weisstein, Sep 29 2021
a(15)-a(24) from Peter J. Taylor, May 20 2023
STATUS
approved

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Last modified June 17 21:09 EDT 2024. Contains 373464 sequences. (Running on oeis4.)