OFFSET
0,3
COMMENTS
Equals the INVERT transform of [1, -1, -1, 1, 1, -1, -1, 1, 1, ...], i.e., 1 followed by repeats of (-1, -1, 1, 1, ...). - Gary W. Adamson, Sep 16 2008
Pisano period lengths: 1, 1, 8, 1, 24, 8, 21, 2, 24, 24, 10, 8, 168, 21, 24, 2, 144, 24, 360, 24, ... - R. J. Mathar, Aug 10 2012
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,-2).
FORMULA
MATHEMATICA
LinearRecurrence[{1, -2}, {1, 0}, 50] (* or *) CoefficientList[Series[(1 - x)/(1-x+2*x^2), {x, 0, 50}], x] (* G. C. Greubel, Jun 29 2019 *)
PROG
(PARI) Vec((1-x)/(1-x+2*x^2)+O(x^50)) \\ Charles R Greathouse IV, Sep 25 2012
(Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( (1-x)/(1-x+2*x^2) )); // G. C. Greubel, Jun 29 2019
(Sage) ((1-x)/(1-x+2*x^2)).series(x, 50).coefficients(x, sparse=False) # G. C. Greubel, Jun 29 2019
(GAP) a:=[1, 0];; for n in [2..50] do a[n]:=a[n-1]-2*a[n-2]; od; a; # G. C. Greubel, Jun 29 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved