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 A199127 Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and no element equal to any horizontal or vertical neighbor 2
 1, 2, 2, 12, 30, 30, 210, 560, 560, 4200, 11550, 11550, 90090, 252252, 252252, 2018016, 5717712, 5717712, 46558512, 133024320, 133024320, 1097450640, 3155170590, 3155170590, 26293088250, 75957810500, 75957810500, 638045608200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 2 of A199133 LINKS R. H. Hardin, Table of n, a(n) for n = 1..198 FORMULA Conjecture: a(3n+2) = a(3n+3) = A208881(n+1). - R. J. Mathar, Nov 01 2015 Conjecture: -(458*n-1205) *(n+2) *(n+1)*a(n) +(-208*n^3+2578*n^2-4613*n-2410) *a(n-1) +9*(-339*n-638) *a(n-2) +27*(n-2) *(458*n^2-289*n-1146) *a(n-3) +54*(n-2) *(n-3) *(104*n-1081) *a(n-4)=0. - R. J. Mathar, Nov 01 2015 Conjecture: (n+2)*(n+1)*a(n) +(5*n^2-2)*a(n-1) +3*(5*n^2-15*n+3) *a(n-2) +3*(n^2 -60*n +81)*a(n-3) +135*(-n^2+3*n-1)*a(n-4) -405*(n-2)*(n-4) *a(n-5) -810*(n-4) *( n-5) *a(n-6)=0. - R. J. Mathar, Nov 01 2015 EXAMPLE Some solutions for n=5 ..0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1 ..1..0....1..2....1..2....1..2....1..0....1..2....1..0....1..2....1..2....1..0 ..0..2....2..0....0..1....2..0....0..2....2..1....0..2....0..1....2..0....2..1 ..2..1....0..2....2..0....0..1....2..1....1..0....2..0....1..2....0..1....1..2 ..0..2....2..1....0..2....2..0....1..2....0..2....1..2....2..0....1..2....2..0 CROSSREFS Sequence in context: A287629 A324919 A130306 * A093044 A151366 A184944 Adjacent sequences:  A199124 A199125 A199126 * A199128 A199129 A199130 KEYWORD nonn AUTHOR R. H. Hardin Nov 03 2011 STATUS approved

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Last modified February 26 02:19 EST 2020. Contains 332270 sequences. (Running on oeis4.)