OFFSET
0,3
LINKS
Robert Israel, Table of n, a(n) for n = 0..4978
Index entries for linear recurrences with constant coefficients, signature (0,0,4).
FORMULA
a(n) = 2^A004523(n).
G.f.: (1+x+2*x^2)/(1-4*x^3). - Robert Israel, Sep 01 2017
From Amiram Eldar, Sep 29 2022: (Start)
Sum_{n>=0} 1/a(n) = 10/3.
Sum_{n>=0} (-1)^n/a(n) = 2/5. (End)
MAPLE
seq(2^floor(2*n/3), n=0..100); # Robert Israel, Sep 01 2017
MATHEMATICA
LinearRecurrence[{0, 0, 4}, {1, 1, 2}, 41] (* Jean-François Alcover, Apr 02 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Don Reble and N. J. A. Sloane, Aug 31 2017
STATUS
approved