OFFSET
1,1
COMMENTS
For an introduction to reductions of polynomials by substitutions such as x^2->x+1, see A192232.
FORMULA
Conjectures from Colin Barker, Jun 07 2019: (Start)
G.f.: x*(4 - 7*x - x^2 + x^3) / ((1 - 3*x + x^2)*(1 - x - x^2)).
a(n) = 4*a(n-1) - 3*a(n-2) - 2*a(n-3) + a(n-4) for n>4.
(End)
EXAMPLE
MATHEMATICA
(See A192472.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jul 01 2011
STATUS
approved