OFFSET
0,2
COMMENTS
Growth series for Z as generated by {2,3}.
REFERENCES
Avinoam Mann, How Groups Grow, London Mathematical Society Lecture Note Series, Vol. 335, Cambridge University Press, 2012; ISBN: 1107657504,9781107657502. See Example 6, page 3.
LINKS
Paolo Xausa, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
From Elmo R. Oliveira, Dec 02 2025: (Start)
G.f.: (1 + 3*x + 4*x^2 - 2*x^3)/(x - 1)^2.
E.g.f.: (1 + 6*x)*exp(x) - 2*x.
a(n) = 2*a(n-1) - a(n-2) for n >= 4. (End)
MATHEMATICA
Accumulate[PadRight[{1, 4, 8}, 100, 6]] (* Paolo Xausa, Nov 14 2023 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jun 21 2019
STATUS
approved
