OFFSET
0,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
N. J. A. Sloane, Transforms
Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,4).
FORMULA
a(n) = Sum_{j=0..n} (-1)^j*binomial(n, j)*A074062(j)
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 4*a(n-5), a(0) = 5, a(1) = 6, a(2) = 6, a(3) = 6, a(4) = 6.
G.f.: (5 -24*x +45*x^2 -40*x^3 +15*x^4)/(1 -6*x +15*x^2 -20*x^3 +15*x^4 -4*x^5).
MATHEMATICA
CoefficientList[Series[(5-24x+45x^2-40x^3+15x^4)/(1-6x+15x^2-20x^3+15x^4-4x^5), {x, 0, 35}], x]
PROG
(Magma)
R<x>:=PowerSeriesRing(Integers(), 40);
Coefficients(R!( (5-24*x+45*x^2-40*x^3+15*x^4)/(1-6*x+15*x^2-20*x^3+15*x^4 -4*x^5) )); // G. C. Greubel, Jul 08 2021
(Sage)
def A168823_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( (5-24*x+45*x^2-40*x^3+15*x^4)/(1-6*x+15*x^2-20*x^3+15*x^4-4*x^5) ).list()
A168823_list(40) # G. C. Greubel, Jul 08 2021
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Mario Catalani (mario.catalani(AT)unito.it), Sep 10 2002
STATUS
approved