OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000 (terms 0..200 from T. D. Noe)
Index entries for linear recurrences with constant coefficients, signature (2, 17).
FORMULA
From Philippe Deléham, Dec 12 2006: (Start)
a(n) = 2*a(n-1) + 17*a(n-2), with a(0)=0, a(1)=3.
G.f.: 3*x/(1-2*x-17*x^2). (End)
MATHEMATICA
Expand[Table[((1+3Sqrt[2])^n -(1-3Sqrt[2])^n)/(2Sqrt[2]), {n, 0, 30}]]
LinearRecurrence[{2, 17}, {0, 3}, 30] (* T. D. Noe, Mar 28 2012 *)
PROG
(PARI) my(x='x+O('x^30)); concat([0], Vec(3*x/(1-2*x-17*x^2))) \\ G. C. Greubel, Aug 02 2019
(Magma) I:=[0, 3]; [n le 2 select I[n] else 2*Self(n-1) +17*Self(n-2): n in [1..30]]; // G. C. Greubel, Aug 02 2019
(Sage) (3*x/(1-2*x-17*x^2)).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, Aug 02 2019
(GAP) a:=[0, 3];; for n in [3..30] do a[n]:=2*a[n-1]+17*a[n-2]; od; a; # G. C. Greubel, Aug 02 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 10 2006
STATUS
approved