OFFSET
4,1
COMMENTS
Also the number of independent vertex sets in the complement of the n-wheel graph. - Eric W. Weisstein, Oct 11 2023
LINKS
Eric Weisstein's World of Mathematics, Clique
Eric Weisstein's World of Mathematics, Independent Vertex Set
Eric Weisstein's World of Mathematics, Wheel Complement Graph
Eric Weisstein's World of Mathematics, Wheel Graph
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 4*n-2 for n > 4.
From Colin Barker, Nov 07 2020: (Start)
G.f.: 2*x^4*(8 - 7*x + x^2) / (1 - x)^2.
a(n) = 2*a(n-1) - a(n-2) for n>6.
(End)
MATHEMATICA
CoefficientList[Series[2 (8 - 7 x + x^2)/(1 - x)^2, {x, 0, 60}], x] (* Wesley Ivan Hurt, Nov 07 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jun 10 2019
EXTENSIONS
Edited by Robert Israel, Jun 12 2019
STATUS
approved