A308144 Number of (undirected) Hamiltonian paths on the triangular grid with n vertices on each side.

1, 3, 12, 114, 1968, 66312, 4381020, 578266212, 153350225268, 82409298702462, 90180040305841212, 201800030110625440248, 926548406689594565864346, 8752381854153235620928637604

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Eric Weisstein's World of Mathematics, Hamiltonian Path

Eric Weisstein's World of Mathematics, Triangular Grid Graph

Formula

a(n) = A112675(n)/2 for n > 1.

Crossrefs

Cf. A112675, A112676, A266513, A288148.

Sequence in context: A032113 A352637 A119649 * A320257 A350410 A009254

Adjacent sequences: A308141 A308142 A308143 * A308145 A308146 A308147

Keyword

nonn

Author

Eric W. Weisstein, May 14 2019

Extensions

a(1) corrected by Andrew Howroyd, Jan 19 2022

Status

approved