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A335610
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Number of sets (in the Hausdorff metric geometry) at each location between two sets defined by a K(5,n) (with n at least 2) complete bipartite graph missing one edge.
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0
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80, 6800, 316928, 11784608, 397551920, 12828154160, 405380093408, 12683426301248, 394943123789840, 12269641330477520, 380755304897252288, 11809363300986469088, 366179512530595589360, 11352903763691009133680, 351960100658771425777568, 10911064386177197162304128
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OFFSET
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2,1
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COMMENTS
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Number of {0,1} 5 X n matrices (with n at least 2) with one fixed zero entry and no zero rows or columns.
Number of edge covers of a K(5,n) complete bipartite graph (with n at least 2) missing one edge.
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LINKS
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FORMULA
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a(n) = 15*31^(n-1) - 43*15^(n-1) + 46*7^(n-1) - 22*3^(n-1) + 4.
G.f.: 16*x^2*(5 + 140*x + 593*x^2 + 522*x^3)/(1 - 57*x + 1002*x^2 - 6562*x^3 + 15381*x^4 - 9765*x^5).
a(n) = 57*a(n-1) - 1002*a(n-2) + 6562*a(n-3) - 15381*a(n-4) + 9765*a(n-5) for n > 6. (End)
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EXAMPLE
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For n = 2, a(2) = 80.
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MATHEMATICA
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Array[15*31^(# - 1) - 43*15^(# - 1) + 46*7^(# - 1) - 22*3^(# - 1) + 4 &, 16, 2] (* Michael De Vlieger, Jun 22 2020 *)
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CROSSREFS
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Sequences of segments from removing edges from bipartite graphs A335608-A335613, A337416-A337418, A340173-A340175, A340199-A340201, A340897-A340899, A342580, A342796, A342850, A340403-A340405, A340433-A340438, A341551-A341553, A342327-A342328, A343372-A343374, A343800. Polygonal chain sequences A152927, A152928, A152929, A152930, A152931, A152932, A152933, A152934, A152939. Number of {0,1} n X n matrices with no zero rows or columns A048291.
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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