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A231544 T(n,k)=Number of nXk 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors 8

%I #4 Nov 10 2013 16:30:22

%S 2,2,2,4,6,4,7,20,20,7,12,57,116,57,12,21,164,589,589,164,21,37,485,

%T 3001,5235,3001,485,37,65,1424,15644,46122,46122,15644,1424,65,114,

%U 4169,81179,417298,698721,417298,81179,4169,114,200,12228,420243,3763223,10928292

%N T(n,k)=Number of nXk 0..1 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors

%C Table starts

%C ...2.....2........4..........7...........12..............21................37

%C ...2.....6.......20.........57..........164.............485..............1424

%C ...4....20......116........589.........3001...........15644.............81179

%C ...7....57......589.......5235........46122..........417298...........3763223

%C ..12...164.....3001......46122.......698721........10928292.........170393737

%C ..21...485....15644.....417298.....10928292.......296647240........8028429092

%C ..37..1424....81179....3763223....170393737......8028429092......377320795091

%C ..65..4169...420243...33812753...2643967833....216093538039....17623244476340

%C .114.12228..2177937..304137386..41079980720...5824887373442...824325064919737

%C .200.35868.11287977.2736503160.638622184605.157116139854017.38588079925163243

%H R. H. Hardin, <a href="/A231544/b231544.txt">Table of n, a(n) for n = 1..311</a>

%F Empirical for column k:

%F k=1: a(n) = 2*a(n-1) -a(n-2) +a(n-3) for n>4

%F k=2: a(n) = 4*a(n-1) -4*a(n-2) +5*a(n-3) -8*a(n-4) +3*a(n-5) -2*a(n-6) +a(n-7) -a(n-8)

%F k=3: [order 22]

%F k=4: [order 61]

%e Some solutions for n=4 k=4

%e ..1..1..1..0....1..1..0..0....1..0..0..0....0..0..1..1....0..0..0..0

%e ..0..0..0..0....1..0..0..0....1..0..1..0....1..0..0..0....0..0..1..0

%e ..0..0..1..1....0..0..0..0....0..1..1..0....0..0..1..0....0..1..0..0

%e ..1..0..0..0....0..0..0..0....0..0..0..1....0..0..0..0....0..0..1..0

%Y Column 1 is A005251(n+2)

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_, Nov 10 2013

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Last modified April 25 05:56 EDT 2024. Contains 371964 sequences. (Running on oeis4.)