OFFSET
0,1
COMMENTS
a(n) gives the time complexity of a recursive Fibonacci algorithm.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,0,-1).
FORMULA
a(0)=2, a(1)=3, a(n) = 3 + a(n-1) + a(n-2) n >= 2.
From R. J. Mathar, Dec 06 2009: (Start)
a(n) = 2*a(n-1) - a(n-3) = A022095(n+1) - 3.
G.f.: (2-x+2*x^2)/((x-1)*(x^2+x-1)). (End)
MATHEMATICA
LinearRecurrence[{2, 0, -1}, {2, 3, 8}, 50] (* Harvey P. Dale, Mar 19 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Manfred Jackel (jkl(AT)uni-koblenz.de), Dec 05 2009
STATUS
approved