A333812 Number of self-avoiding paths joining opposite corners of 7 X n board.

1, 64, 1369, 29739, 752061, 20562673, 575780564, 16230458696, 459133264944, 13021391001373, 369886375079581, 10516022622412960, 299104709252534435, 8509249843020438582, 242108399244641421526, 6888987223916209602814, 196026708756588099010848

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..400

Prog

(Python)
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A064298(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)
    return paths.len()
def A333812(n):
    return A064298(n, 7)
print([A333812(n) for n in range(1, 20)])

Crossrefs

Row 7 of A064298.

Sequence in context: A240294 A226086 A017031 * A283812 A264086 A239442

Adjacent sequences: A333809 A333810 A333811 * A333813 A333814 A333815

Keyword

nonn

Author

Seiichi Manyama, Apr 06 2020

Status

approved