

A177369


Expansion of g.f.: (1+4*x4*x^2)/(13*x4*x^2+4*x^3)


2



1, 7, 21, 87, 317, 1215, 4565, 17287, 65261, 246671, 931909, 3521367, 13305053, 50272991, 189953717, 717732903, 2711921613, 10246881583, 38717399589, 146292038647
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OFFSET

1,2


REFERENCES

S. Kitaev, A. Burstein and T. Mansour. Counting independent sets in certain classes of (almost) regular graphs, Pure Mathematics and Applications (PU.M.A.) 19 (2008), no. 23, 1726.


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000
S. Kitaev, A. Burstein and T. Mansour. Counting independent sets in certain classes of (almost) regular graphs
Index entries for linear recurrences with constant coefficients, signature (3,4,4).


FORMULA

G.f.:(1+4*x4*x^2)/(13*x4*x^2+4*x^3)
a(1)=1, a(2)=7, a(3)=21, a(n)=3*a(n1)+4*a(n2)4*a(n3).  Harvey P. Dale, May 10 2015


MATHEMATICA

CoefficientList[Series[(1+4x4x^2)/(13x4x^2+4x^3), {x, 0, 20}], x] (* or *) LinearRecurrence[{3, 4, 4}, {1, 7, 21}, 20] (* Harvey P. Dale, May 10 2015 *)


CROSSREFS

Sequence in context: A110683 A092785 A114902 * A164544 A100025 A121157
Adjacent sequences: A177366 A177367 A177368 * A177370 A177371 A177372


KEYWORD

nonn


AUTHOR

Signy Olafsdottir (signy06(AT)ru.is), May 07 2010


EXTENSIONS

Definition clarified by Harvey P. Dale, May 10 2015


STATUS

approved



