OFFSET
1,1
REFERENCES
F. Faase, On the number of specific spanning subgraphs of the graphs G X P_n, Ars Combin. 49 (1998), 129-154.
Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research report, No 12, 1996, Department of Math., Umea University, Sweden.
LINKS
F. 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.
F. Faase, Results from the counting program
Per Hakan Lundow, Enumeration of matchings in polygraphs, 1998.
Index entries for linear recurrences with constant coefficients, signature (19, -41, 19, -1).
FORMULA
a(n) = 19a(n-1) - 41a(n-2) + 19a(n-3) - a(n-4), n>4.
G.f. x*(11-33*x+18*x^2-x^3)/(1-19*x+41*x^2-19*x^3+x^4) . [From R. J. Mathar, Mar 11 2010]
MATHEMATICA
Rest[CoefficientList[Series[x (11-33x+18x^2-x^3)/(1-19x+41x^2- 19x^3+ x^4), {x, 0, 20}], x]] (* or *) LinearRecurrence[{19, -41, 19, -1}, {11, 176, 2911, 48301}, 20] (* Harvey P. Dale, Jul 16 2011 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved