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URL: https://oeis.org/A307930

⇱ A307930 - OEIS

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A307930
Number of (undirected) Hamiltonian circuits in the n-triangular graph.
0
0, 1, 16, 3216, 9748992, 554701578240, 690468767270830080
OFFSET
2,3
LINKS
Eric Weisstein's World of Mathematics, Hamiltonian Cycle
Eric Weisstein's World of Mathematics, Triangular Graph
FORMULA
a(n) = A129349(n)/2.
EXAMPLE
The sequence starts from a(2) because graph T(1) has no vertices.
a(2)=0 because graph T(2) is the singleton graph with no circuits.
a(3)=1 becaues graph T(3) is the cycle graph C3 with one circuit.
CROSSREFS
Cf. A129349.
Sequence in context: A049030 A223068 A051551 * A289703 A266824 A249599
KEYWORD
nonn,more,hard
AUTHOR
Eric W. Weisstein, May 06 2019
EXTENSIONS
One leading 0 term removed by Martin Fuller, Mar 15 2026
STATUS
approved