OFFSET
1,1
COMMENTS
For an introduction to reductions of polynomials by substitutions such as x^2->x+3, see A192232.
FORMULA
Empirical G.f.: -2*x*(x-1)*(3*x-1)/((3*x^2+x-1)*(9*x^2-7*x+1)). [Colin Barker, Nov 12 2012]
EXAMPLE
MATHEMATICA
(See A192468.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jul 01 2011
STATUS
approved