OFFSET
1,3
COMMENTS
FORMULA
Conjecture: a(n) = 2*a(n-1)+6*a(n-2)-2*a(n-3)-a(n-4). G.f.: x^2*(x^2+1) / (x^4+2*x^3-6*x^2-2*x+1). [Colin Barker, Jan 17 2013]
EXAMPLE
MATHEMATICA
(See A192346.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 28 2011
STATUS
approved