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A101825
G.f.: x*(1+x)^2/(1-x^3).
3
0, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2
OFFSET
0,3
COMMENTS
Period 3. Used in A042965.
First differences are essentially A049347. The binomial transform yields 0, 1, 4, 10,... i.e. A111927 with the first two zeros removed. - R. J. Mathar, May 14 2008
FORMULA
a(n) = A100063(n+1), n>0. - R. J. Mathar, Sep 01 2008
MATHEMATICA
LinearRecurrence[{0, 0, 1}, {0, 1, 2, 1}, 120] (* Harvey P. Dale, Aug 01 2016 *)
PROG
(PARI) x='x+O('x^50); Vec(x*(1+x)^2/(1-x^3)) \\ G. C. Greubel, May 03 2017
CROSSREFS
Sequence in context: A107751 A132367 A087204 * A177702 A131534 A061347
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jun 17 2007
STATUS
approved