OFFSET
0,2
COMMENTS
E(L_5,L_{2n-1}) is the graph with vertices {(a,b) : 1<=a<=5, 1<=b<=2n-1, a+b even and edges between (a,b) and (c,d) if and only if |a-b|=|c-d|=1.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..200
Eric Weisstein's World of Mathematics, Independent Vertex Set
Z. Zhang, Merrifield-Simmons index of generalized Aztec diamond and related graphs, MATCH Commun. Math. Comput. Chem. 56 (2006) 625-636.
Index entries for linear recurrences with constant coefficients, signature (12,-24,5).
FORMULA
Empirical g.f.: -(x^2-4*x+1) / (5*x^3-24*x^2+12*x-1). - Colin Barker, Jan 26 2015
The above g.f. is correct. See A331406 for bounds on the order of the recurrence. - Andrew Howroyd, Jan 16 2020
PROG
(PARI) Vec((1 - 4*x + x^2)/(1 - 12*x + 24*x^2 - 5*x^3) + O(x^25)) \\ Andrew Howroyd, Jan 16 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Steve Butler, Jan 26 2015
EXTENSIONS
Terms a(12) and beyond from Andrew Howroyd, Jan 15 2020
STATUS
approved