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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
OFFSET
0,2
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
Sequence in context: A223354 A236941 A222141 * A185924 A013997 A118056
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 27 2020
EXTENSIONS
Terms a(7) and beyond from Andrew Howroyd, Jan 30 2022
STATUS
approved