On Jul 18, 2010, at 12:18 PM, Ron Hardin wrote: > So the gf denominator sequence is > (2*x-1)*(x-1)^3 > (2*x-1)^2*(x-1)^4 > (-1+3*x)*(2*x-1)^3*(x-1)^5 > (-1+3*x)^2*(2*x-1)^4*(x-1)^6 So, (x-1)^n (2x-1)^(n-2) (3x-1)^(n-4), presumably (4x-1)^(n-6), etc... and the numerators? Get those and we've got a formula. William Keith