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A268369
Number of 3 X n arrays containing n copies of 0..3-1 with row sums equal.
1
0, 12, 216, 2700, 54000, 1054200, 20991600, 445365900, 9628264800, 212635396512, 4790810344320, 109495671909624, 2534856710978592, 59336480231336880, 1402136110916757216, 33409975384414912140, 801962422581013417152
OFFSET
1,2
COMMENTS
Row 3 of A268367.
LINKS
FORMULA
Conjecture: n^4*(1057*n^2 -3473*n +2902)*a(n) -(n-1) *(14798*n^5 -63420*n^4 +104199*n^3 -81821*n^2 +31698*n -4968)*a(n-1) +(-235711*n^6 +1717323*n^5 -5084885*n^4 +7773081*n^3 -6422772*n^2 +2716308*n -472176)*a(n-2) -96*(6*n -11) *(6*n-13) *(1057*n^2-1359*n+486) *(n-2)^2*a(n-3)=0. - R. J. Mathar, Feb 18 2016
EXAMPLE
Some solutions for n=5
..1..1..1..0..2....0..0..2..2..1....1..0..2..1..1....0..1..2..0..2
..0..1..0..2..2....1..1..1..2..0....1..0..2..0..2....0..1..1..1..2
..0..0..2..2..1....0..1..2..0..2....0..0..2..1..2....2..0..0..1..2
CROSSREFS
Cf. A268367.
Sequence in context: A241225 A274956 A116164 * A091266 A119309 A034788
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 03 2016
STATUS
approved