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 A333247 Number of self-avoiding closed paths on an n X n grid which pass through NW and SW corners. 5
 1, 4, 47, 1843, 232905, 92729439, 115234959344, 442748883422394 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 COMMENTS a(11) = 188829168009674568016545. - Seiichi Manyama, Apr 07 2020 LINKS Table of n, a(n) for n=2..9. EXAMPLE a(2) = 1; +--* | | +--* a(3) = 4; +--*--* +--*--* +--* +--* | | | | | | | | * * * *--* * *--* * * | | | | | | | | +--*--* +--* +--*--* +--* PROG (Python) # Using graphillion from graphillion import GraphSet import graphillion.tutorial as tl def A333247(n): universe = tl.grid(n - 1, n - 1) GraphSet.set_universe(universe) cycles = GraphSet.cycles().including(1).including(n) return cycles.len() print([A333247(n) for n in range(2, 10)]) CROSSREFS Cf. A271507, A333246, A333323, A333466. Sequence in context: A251665 A210828 A361560 * A330039 A141040 A182102 Adjacent sequences: A333244 A333245 A333246 * A333248 A333249 A333250 KEYWORD nonn,more AUTHOR Seiichi Manyama, Mar 23 2020 STATUS approved

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Last modified December 4 15:16 EST 2023. Contains 367563 sequences. (Running on oeis4.)