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A333583 Number of Hamiltonian paths in an 8 X (2n+1) grid starting at the lower left corner and finishing in the upper right corner. 3
1, 64, 6706, 851073, 114243216, 15695570146, 2178079125340, 303568139329711, 42388918310108440, 5923750747499881068, 828111786035239457647, 115782566867663040724929, 16189114623816733581826838, 2263672174616450290622937801, 316525123224847580237219904819 (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 A333583(n):

    return A333580(8, 2 * n + 1)

print([A333583(n) for n in range(7)])

CROSSREFS

Cf. A014523, A333580.

Sequence in context: A085525 A349506 A264188 * A183243 A264075 A223198

Adjacent sequences:  A333580 A333581 A333582 * A333584 A333585 A333586

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 June 26 04:31 EDT 2022. Contains 354877 sequences. (Running on oeis4.)