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A333585 Number of Hamiltonian paths in a 10 X (2n+1) grid starting at the lower left corner and finishing in the upper right corner. 4
1, 256, 117204, 68939685, 43598351250, 28467653231928, 18879702000329222, 12620031290571348940, 8469937551020819909757, 5696439378813116535052879, 3835239247888770485464962184, 2583576672252172117218927779417, 1740899369113326621618848563838108 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..200

Index entries for sequences related to graphs, Hamiltonian

PROG

(Python)

# Using graphillion

from graphillion import GraphSet

import graphillion.tutorial as tl

def A333580(n, k):

    if n == 1 or k == 1: return 1

    universe = tl.grid(n - 1, k - 1)

    GraphSet.set_universe(universe)

    start, goal = 1, k * n

    paths = GraphSet.paths(start, goal, is_hamilton=True)

    return paths.len()

def A333585(n):

    return A333580(10, 2 * n + 1)

print([A333585(n) for n in range(7)])

CROSSREFS

Cf. A014523, A333580.

Sequence in context: A223354 A236941 A222141 * A185924 A013997 A118056

Adjacent sequences:  A333582 A333583 A333584 * A333586 A333587 A333588

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Mar 27 2020

EXTENSIONS

Terms a(7) and beyond from Andrew Howroyd, Jan 30 2022

STATUS

approved

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Last modified August 18 22:18 EDT 2022. Contains 356215 sequences. (Running on oeis4.)