OFFSET
3,1
REFERENCES
Henning, Michael A., A survey of selected recent results on total domination in graphs. Discrete Math. 309 (2009), no. 1, 32-63.
LINKS
Colin Barker, Table of n, a(n) for n = 3..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
For n >= 9, a(n) = 2n-3.
G.f.: x^3*(3 - 2*x + x^2 - x^3 + x^4 + 2*x^6 - 2*x^7) / (1 - x)^2. - Colin Barker, Dec 25 2019
MATHEMATICA
LinearRecurrence[{2, -1}, {3, 4, 6, 7, 9, 11, 15, 17}, 80] (* Harvey P. Dale, Nov 07 2021 *)
PROG
(PARI) Vec(x^3*(3 - 2*x + x^2 - x^3 + x^4 + 2*x^6 - 2*x^7) / (1 - x)^2 + O(x^70)) \\ Colin Barker, Dec 25 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 01 2011
STATUS
approved