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A333863 Number of Hamiltonian paths in a 2*(2*n+1) X (2*n+1) grid starting at the upper left corner and finishing in the lower right corner. 3
1, 16, 117204, 440051896440, 825830699757513748579, 769203260676279544212492116449800, 354179806054404909542325896762875458037457353029 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..6.

FORMULA

a(n) = A333580(2*(2*n+1), 2*n+1).

PROG

(Python)

# Using graphillion

from graphillion import GraphSet

import graphillion.tutorial as tl

def A333863(n):

    universe = tl.grid(4 * n + 1, 2 * n)

    GraphSet.set_universe(universe)

    start, goal = 1, 2 * (2 * n + 1) ** 2

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

    return paths.len()

print([A333863(n) for n in range(7)])

CROSSREFS

Cf. A001184, A333580, A333585, A333864.

Sequence in context: A144830 A278289 A298202 * A300197 A297386 A051675

Adjacent sequences:  A333859 A333860 A333861 * A333864 A333865 A333866

KEYWORD

nonn,more

AUTHOR

Seiichi Manyama, Apr 08 2020

STATUS

approved

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Last modified June 4 08:18 EDT 2020. Contains 334825 sequences. (Running on oeis4.)