OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000 (* terms 0..144 from Vincenzo Librandi)
Index entries for linear recurrences with constant coefficients, signature (10, -17).
FORMULA
a(n) = 10*a(n-1) - 17*a(n-2) for n > 1; a(0) = 1, a(1) = 8.
a(n) = ((4 + sqrt(18))*(5 + sqrt(8))^n + (4 - sqrt(18))*(5 - sqrt(8))^n)/8.
G.f.: (1-2*x)/(1-10*x+17*x^2).
E.g.f.: (1/4)*exp(5*x)*(4*cosh(2*sqrt(2)*x) + 3*sqrt(2)*sinh(2*sqrt(2)*x)). - G. C. Greubel, Aug 12 2017
MATHEMATICA
CoefficientList[Series[(1 - 2*z)/(17*z^2 - 10*z + 1), {z, 0, 200}], z] (* Vladimir Joseph Stephan Orlovsky, Jun 12 2011 *)
LinearRecurrence[{10, -17}, {1, 8}, 30] (* Harvey P. Dale, Oct 14 2012 *)
PROG
(Magma) Z<x>:=PolynomialRing(Integers()); N<r>:=NumberField(x^2-2); S:=[ ((4+3*r)*(5+2*r)^n+(4-3*r)*(5-2*r)^n)/8: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 24 2009
(PARI) x='x+O('x^50); Vec((1-2*x)/(1-10*x+17*x^2)) \\ G. C. Greubel, Aug 12 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Al Hakanson (hawkuu(AT)gmail.com), Aug 17 2009
EXTENSIONS
Extended by Klaus Brockhaus and R. J. Mathar Aug 24 2009
STATUS
approved