OFFSET
0,4
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0, 3, 0, 1, 0, 1).
FORMULA
MAPLE
A075536 := proc(n)
if type(n, 'even') then
A000073(n+1) ;
else
A001644(n) ;
end if;
end proc:
seq(A075536(n), n=0..80) ; # R. J. Mathar, Aug 05 2021
MATHEMATICA
CoefficientList[Series[(x+x^2+4x^3+x^4-x^5)/(1-3x^2-x^4-x^6), {x, 0, 40}], x]
LinearRecurrence[{0, 3, 0, 1, 0, 1}, {0, 1, 1, 7, 4, 21}, 40] (* Harvey P. Dale, Jul 10 2012 *)
PROG
(PARI) my(x='x+O('x^40)); concat([0], Vec(x*(1+x+4*x^2+x^3-x^4)/(1-3*x^2-x^4-x^6))) \\ G. C. Greubel, Apr 21 2019
(Magma) R<x>:=PowerSeriesRing(Integers(), 40); [0] cat Coefficients(R!( x*(1+x+4*x^2+x^3-x^4)/(1-3*x^2-x^4-x^6) )); // G. C. Greubel, Apr 21 2019
(Sage) (x*(1+x+4*x^2+x^3-x^4)/(1-3*x^2-x^4-x^6)).series(x, 40).coefficients(x, sparse=False) # G. C. Greubel, Apr 21 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Mario Catalani (mario.catalani(AT)unito.it), Sep 23 2002
EXTENSIONS
Index in definition corrected. - R. J. Mathar, Aug 05 2021
STATUS
approved