OFFSET
1,3
COMMENTS
Limit ratio is 1.839286755214161 ...
Last digit sequence has a period of 1860, starting from 3rd element.
LINKS
Index entries for linear recurrences with constant coefficients, signature (2,1,-1,-2,-1).
FORMULA
G.f.: x+x^2 -x^3*(1+x)*(x^2+3*x-2) / ( (x^2+x-1)*(x^3+x^2+x-1) ). - R. J. Mathar, Feb 16 2011
EXAMPLE
a(10) = 65 = Fib(9) + Trib(7) = 34 + 31.
MATHEMATICA
Rest[CoefficientList[Series[x+x^2-x^3(1+x)(x^2+3*x-2)/((x^2+x-1)(x^3+x^2+x-1)), {x, 0, 50}], x]] (* Harvey P. Dale, Feb 24 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Carmine Suriano, Feb 16 2011
STATUS
approved