OFFSET
1,4
COMMENTS
Column 3 of A180760
LINKS
R. H. Hardin, Table of n, a(n) for n=1..99
FORMULA
Empirical: a(n) = 2*a(n-1) + a(n-2) - a(n-3) - a(n-5).
Empirical: G.f.: -x^2*(-1+x+x^3+x^2) / ( (x-1)*(1+x)*(x^3+2*x-1) ). a(n)-a(n-2) = A052980(n-3). - R. J. Mathar, Mar 24 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 20 2010
STATUS
approved