OFFSET
1,1
LINKS
Frans J. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Preliminary version of paper that appeared in Ars Combin. 49 (1998), 129-154.
Frans J. Faase, Counting Hamiltonian cycles in product graphs
Frans J. Faase, Results from the counting program
Index entries for linear recurrences with constant coefficients, signature (7,-2).
FORMULA
a(n) = 7*a(n-1) - 2*a(n-2), n>3.
G.f.: 3*x*(1+3*x-2*x^2)/(1-7*x+2*x^2). - R. J. Mathar, Dec 16 2008
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from Stefano Spezia, May 13 2023
STATUS
approved