A290612 Number of maximal independent vertex sets (and minimal vertex covers) in the n-wheel graph.

4, 3, 6, 6, 8, 11, 13, 18, 23, 30, 40, 52, 69, 91, 120, 159, 210, 278, 368, 487, 645, 854, 1131, 1498, 1984, 2628, 3481, 4611, 6108, 8091, 10718, 14198, 18808, 24915, 33005, 43722, 57919, 76726, 101640, 134644, 178365, 236283, 313008, 414647, 549290, 727654, 963936

Offset

4,1

Links

Table of n, a(n) for n=4..50.

Eric Weisstein's World of Mathematics, Maximal Independent Vertex Set

Eric Weisstein's World of Mathematics, Minimal Vertex Cover

Eric Weisstein's World of Mathematics, Wheel Graph

Index entries for linear recurrences with constant coefficients, signature (1, 1, 0, -1).

Formula

a(n) = a(n-1) + a(n-2) - a(n-4).

G.f.: (x^3 (4 - x - x^2 - 3 x^3))/(1 - x - x^2 + x^4).

Mathematica

Table[1 + RootSum[-1 - # + #^3 &, #^(n - 1) &], {n, 4, 20}]
LinearRecurrence[{1, 1, 0, -1}, {4, 3, 6, 6, 8}, 20]
CoefficientList[Series[(4 - x - x^2 - 3 x^3)/(1 - x - x^2 + x^4), {x, 0, 20}], x]

Crossrefs

Sequence in context: A362449 A021233 A352922 * A292616 A071901 A266576

Adjacent sequences: A290609 A290610 A290611 * A290613 A290614 A290615

Keyword

nonn

Author

Eric W. Weisstein, Aug 07 2017

Status

approved