OFFSET
4,1
LINKS
R. H. Hardin, Table of n, a(n) for n=4..500
Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-1,1,-1).
FORMULA
G.f.: -x^4*(-13+6*x-4*x^2+6*x^3-4*x^4+8*x^5) / ( (x-1)*(x^5+x^3+x-1) ). - R. J. Mathar, Jan 19 2011
MATHEMATICA
LinearRecurrence[{2, -1, 1, -1, 1, -1}, {13, 20, 31, 49, 78, 123}, 40] (* Harvey P. Dale, Sep 22 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Aug 14 2009
STATUS
approved