OFFSET
0,4
FORMULA
Conjectures from Colin Barker, Jan 29 2016: (Start)
a(n) = (2*n-5*((-1)^n-1))/4 for n>2.
a(n) = n/2 for n>2 and even.
a(n) = (n+5)/2 for n>2 and odd.
a(n) = a(n-1)+a(n-2)-a(n-3) for n>5.
G.f.: x*(1-x+3*x^2-x^3-x^4) / ((1-x)^2*(1+x)).
(End)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 17 2016
STATUS
approved