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A273322
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Wiener index of graphs of f.c.c. unit cells in a line = Sum of distances in face-centered cubic grid unit cells connected in a row.
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2
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150, 536, 1336, 2712, 4826, 7840, 11916, 17216, 23902, 32136, 42080, 53896, 67746, 83792, 102196, 123120, 146726, 173176, 202632, 235256, 271210, 310656, 353756, 400672, 451566, 506600, 565936, 629736, 698162, 771376, 849540, 932816, 1021366
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = 27*n^3 + 45*n^2 + 62*n + 16.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n > 4.
G.f.: 2*x*(75 - 32*x + 46*x^2 - 8*x^3) / (1-x)^4.
(End)
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MATHEMATICA
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Table[27 n^3 + 45 n^2 + 62 n + 16, {n, 33}] (* or *)
Rest@ CoefficientList[Series[2 x (75 - 32 x + 46 x^2 - 8 x^3)/(1 - x)^4, {x, 0, 33}], x] (* Michael De Vlieger, May 20 2016 *)
LinearRecurrence[{4, -6, 4, -1}, {150, 536, 1336, 2712}, 40] (* Harvey P. Dale, Dec 04 2018 *)
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PROG
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(PARI) Vec(2*x*(75-32*x+46*x^2-8*x^3)/(1-x)^4 + O(x^50)) \\ Colin Barker, May 20 2016
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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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STATUS
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approved
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