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 A220644 T(n,k) = number of ways to reciprocally link elements of an n X k array either to themselves or to exactly one king-move neighbor. 11
 1, 2, 2, 3, 10, 3, 5, 40, 40, 5, 8, 172, 369, 172, 8, 13, 728, 3755, 3755, 728, 13, 21, 3096, 37320, 92801, 37320, 3096, 21, 34, 13152, 373177, 2226936, 2226936, 373177, 13152, 34, 55, 55888, 3725843, 53841725, 128171936, 53841725, 3725843, 55888, 55, 89 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Table starts ...1........2............3.................5.....................8 ...2.......10...........40...............172...................728 ...3.......40..........369..............3755.................37320 ...5......172.........3755.............92801...............2226936 ...8......728........37320...........2226936.............128171936 ..13.....3096.......373177..........53841725............7444342896 ..21....13152......3725843........1299348473..........431408410784 ..34....55888.....37213728.......31371388772........25014514225856 ..55...237472....371654153......757341382671......1450226501771584 ..89..1009056...3711809483....18283618480037.....84080327982982848 .144..4287616..37070598992...441397115736816...4874715696405194752 .233.18218688.370232236753.10656083384666537.282621433306639435392 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..528 (antidiagonals 1..32) (terms n = 1..180 from R. H. Hardin) EXAMPLE Some solutions for n=3 k=4 0=self 1=nw 2=n 3=ne 4=w 6=e 7=sw 8=s 9=se (reciprocal directions total 10) ..0..6..4..8....6..4..0..0....8..0..0..0....9..6..4..8....6..4..0..0 ..0..7..7..2....8..0..9..7....2..8..8..0....8..1..9..2....0..0..8..8 ..3..3..6..4....2..0..3..1....0..2..2..0....2..6..4..1....0..0..2..2 CROSSREFS Columns k=1-10 give: A000045(n+1), A052978, A220639, A220640, A220641, A220642, A220643, A243314, A243315, A243316. Main diagonal is A220638. Cf. A239264. Sequence in context: A032103 A091044 A079661 * A338372 A153920 A300483 Adjacent sequences: A220641 A220642 A220643 * A220645 A220646 A220647 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Dec 17 2012 STATUS approved

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Last modified December 11 06:34 EST 2023. Contains 367717 sequences. (Running on oeis4.)