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URL: https://oeis.org/A293126

⇱ A293126 - OEIS

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A293126
Number of matchings in the 2n-crossed prism graph.
1
3, 12, 108, 1092, 11208, 115272, 1185888, 12200592, 125522208, 1291399392, 13286195328, 136691243712, 1406309006208, 14468410468992, 148854128491008, 1531443389475072, 15755820002738688, 162099275536276992, 1667712319943927808, 17157784159685102592
OFFSET
0,1
COMMENTS
Extended to a(0)-a(1) using the formula/recurrence.
LINKS
Eric Weisstein's World of Mathematics, Crossed Prism Graph
Eric Weisstein's World of Mathematics, Independent Vertex Set
Eric Weisstein's World of Mathematics, Vertex Cover
FORMULA
a(n) = 12*a(n-1) - 18*a(n-2) + 4*a(n-3).
G.f.: -3*x*(1 - 8*x + 6*x^2)/(-1 + 12*x - 18*x^2 + 4*x^3).
MATHEMATICA
RootSum[-4 + 18 # - 12 #^2 + #^3 &, #^Range[0, 20] &]
Table[RootSum[-4 + 18 # - 12 #^2 + #^3 &, #^n &], {n, 0, 20}]
LinearRecurrence[{12, -18, 4}, {12, 108, 1092}, {0, 20}]
CoefficientList[Series[-3 (1 - 8 x + 6 x^2)/(-1 + 12 x - 18 x^2 + 4 x^3), {x, 0, 20}], x]
CROSSREFS
Sequence in context: A324313 A377578 A111485 * A080447 A127059 A178013
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Sep 30 2017
STATUS
approved