OFFSET
0,8
COMMENTS
a(n+5) is the Hankel transform of A052702(n+4).
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,0,-4,0,0,-6,0,0,-4,0,0,-1).
FORMULA
G.f.: x^4*(1-x)*(1+x+x^2)*(x^4+x^3-x^2+x+1)/( (1+x)^4*(x^2-x+1)^4 ).
a(n) = -4*a(n-3) -6*a(n-6) -4*a(n-9) -a(n-12).
MATHEMATICA
LinearRecurrence[{0, 0, -4, 0, 0, -6, 0, 0, -4, 0, 0, -1}, {0, 0, 0, 0, 1, 1, -1, -4, -4, 5, 9, 9}, 50] (* G. C. Greubel, May 02 2018 *)
PROG
(PARI) x='x+O('x^50); concat([0, 0, 0, 0], Vec(x^4*(1-x)*(1+x+x^2)*(x^4+x^3-x^2+x+1)/( (1+x)^4*(x^2-x+1)^4 ))) \\ G. C. Greubel, May 02 2018
(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); [0, 0, 0, 0] cat Coefficients(R!(x^4*(1-x)*(1+x+x^2)*(x^4+x^3-x^2+x+1)/( (1+x)^4*(x^2-x+1)^4 ))); // G. C. Greubel, May 02 2018
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, May 24 2009
STATUS
approved