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A333605 Number of directed Hamiltonian walks from NW to SW corners of a 9 X (2*n+1) grid. 1
1, 128, 28002, 7503654, 2087813834, 585874869236, 164719994049404, 46331085939142414, 13032851914297031372, 3666193548666012258524, 1031319586988812684556890, 290115923359022569718438776, 81611236566429170178900484740, 22957699681804739055041075650848 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
PROG
(Python)
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A271592(n, k):
if k == 1: return 1
universe = tl.grid(k - 1, n - 1)
GraphSet.set_universe(universe)
start, goal = 1, n
paths = GraphSet.paths(start, goal, is_hamilton=True)
return paths.len()
def A333605(n):
return A271592(9, 2 * n + 1)
print([A333605(n) for n in range(15)])
CROSSREFS
Row n=9 of A271592 (with 0 omitted).
Cf. A333584.
Sequence in context: A051251 A264346 A189958 * A264189 A264076 A067822
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 28 2020
STATUS
approved

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Last modified April 17 15:20 EDT 2024. Contains 371764 sequences. (Running on oeis4.)