OFFSET
0,1
COMMENTS
Using the indexing convention that DGM(0) = P_2.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..8
Eric Weisstein's World of Mathematics, Dorogovtsev-Goltsev-Mendes Graph.
Eric Weisstein's World of Mathematics, Independent Vertex Set.
FORMULA
a(n) = b(n) + 2*c(n) where b(0) = c(0) = 1 and c(n) = b(n-1)*c(n-1)^2, b(n) = c(n) + b(n-1)^3 for n > 0. - Andrew Howroyd, Dec 30 2023
PROG
(PARI) a(n) = {my(b=1, c=1); for(k=1, n, c = b*c^2; b = b^3 + c); b + 2*c} \\ Andrew Howroyd, Dec 30 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Dec 25 2023
EXTENSIONS
a(0) prepended and terms a(5) and beyond from Andrew Howroyd, Dec 30 2023
STATUS
approved