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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
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 A333583(n):
return A333580(8, 2 * n + 1)
print([A333583(n) for n in range(7)])
CROSSREFS
Sequence in context: A085525 A349506 A264188 * A183243 A264075 A223198
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 27 2020
EXTENSIONS
Terms a(7) and beyond from Andrew Howroyd, Jan 30 2022
STATUS
approved