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A347673
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Number of Baxter matrices of size 3 X n.
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3
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1, 14, 69, 203, 463, 903, 1585, 2579, 3963, 5823, 8253, 11355, 15239, 20023, 25833, 32803, 41075, 50799, 62133, 75243, 90303, 107495, 127009, 149043, 173803, 201503, 232365, 266619, 304503, 346263, 392153, 442435, 497379, 557263, 622373, 693003, 769455, 852039
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = 1/3*n^4 + 3*n^3 - 16/3*n^2 + 2*n + 3 for n >= 3.
G.f.: -x*(x^6 - 3*x^5 + 3*x^4 - 12*x^3 + 9*x^2 + 9*x + 1)/(x - 1)^5. (End)
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MATHEMATICA
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Rest@ CoefficientList[Series[-x (x^6 - 3 x^5 + 3 x^4 - 12 x^3 + 9 x^2 + 9 x + 1)/(x - 1)^5, {x, 0, 38}], x] (* Michael De Vlieger, Oct 20 2021 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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