OFFSET
0,1
COMMENTS
a(n) = 2*A041041(n). Kekulé numbers for certain benzenoids.
REFERENCES
S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 284, K{Q(n)}).
LINKS
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (10, 1).
FORMULA
G.f.: 2/(1-10z-z^2).
MAPLE
a:=n->(1/sqrt(26))*((5+sqrt(26))^(n+1)-(5-sqrt(26))^(n+1)): seq(expand(a(n)), n=0..20);
CROSSREFS
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Jun 19 2005
STATUS
approved