OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (6,-11,6,-1).
FORMULA
From Colin Barker, Nov 30 2012: (Start)
a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4).
G.f.: x*(x^3-x+1)/(x^2-3*x+1)^2. (End)
a(n) = ((3 - n)*Fibonacci(2*n) - (5 - 8*n)*Fibonacci(2*n - 1))/5. - G. C. Greubel, Sep 10 2017
MATHEMATICA
Rest[CoefficientList[Series[x*(x^3 - x + 1)/(x^2 - 3*x + 1)^2, {x, 0, 50}], x]] (* or *) Table[((3 - n)*Fibonacci[2*n] - (5 - 8*n)*Fibonacci[2*n - 1])/5, {n, 1, 50}] (* G. C. Greubel, Sep 10 2017 *)
PROG
(PARI) Vec(x*(x^3-x+1)/(x^2-3*x+1)^2 + O(x^40)) \\ Michel Marcus, Sep 09 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Floor van Lamoen, Jan 19 2001
STATUS
approved