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 A233022 Number of nX4 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero 1
 27, 435, 8835, 179999, 3685017, 75489671, 1546718177, 31692006853, 649369155341, 13305594622397, 272632154901327, 5586243967145293, 114462368539181387, 2345338645585949507, 48056085480976430831, 984671171688465647531 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 4 of A233026 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 23*a(n-1) -39*a(n-2) -265*a(n-3) +180*a(n-4) +655*a(n-5) -156*a(n-6) -127*a(n-7) +20*a(n-8) Empirical: G.f.: -x*(27-186*x-117*x^2+914*x^3+20*x^4-469*x^5+129*x^6)/(-1+23*x-39*x^2-265*x^3+180*x^4+655*x^5-156*x^6-127*x^7+20*x^8) . - R. J. Mathar, May 11 2022 EXAMPLE Some solutions for n=4 ..0..2..2..2....0..0..2..2....0..2..0..0....0..0..1..3....0..0..0..2 ..0..2..2..2....2..2..2..2....2..0..2..0....0..0..1..1....2..2..2..0 ..0..0..0..2....0..2..2..0....0..2..0..2....1..0..1..1....3..2..2..0 ..1..0..2..2....2..2..2..0....2..0..0..0....1..0..0..1....3..2..2..0 CROSSREFS Sequence in context: A125484 A022751 A004326 * A289902 A028166 A028135 Adjacent sequences: A233019 A233020 A233021 * A233023 A233024 A233025 KEYWORD nonn AUTHOR R. H. Hardin, Dec 03 2013 STATUS approved

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Last modified May 28 21:57 EDT 2023. Contains 363028 sequences. (Running on oeis4.)