OFFSET
3,1
COMMENTS
Also the number of independent vertex sets in the complement of the n-cycle graph. - Eric W. Weisstein, Oct 11 2023
LINKS
Andrew Howroyd, Table of n, a(n) for n = 3..1000
Eric Weisstein's World of Mathematics, Clique.
Eric Weisstein's World of Mathematics, Cycle Complement Graph.
Eric Weisstein's World of Mathematics, Cycle Graph.
Eric Weisstein's World of Mathematics, Independent Vertex Set.
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 2*n+1 for n > 3.
G.f.: x^3*(8 - 7*x + x^2)/(1 - x)^2. - Andrew Howroyd, Nov 06 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jun 09 2019
STATUS
approved
