[seqfan] Re: A106804

Simon Plouffe simon.plouffe at gmail.com
Wed Dec 14 00:57:42 CET 2011



Hello,

  from my table of conjectures (automated generated formulas), at
http://www.plouffe.fr/simon/OEIS/conjectures/OEIS_conjectured_formulas.txt

  I get these entries :

A106804 14.8323 -(-2*x+9*x^2+4*x^3)/(1-10*x-x^4+25*x^2) ogf
A106804 15.2226 (-2+9*x+4*x^2)/(x^2-5*x+1)/(x^2+5*x-1) ogf
A106804 6.78608 -10*x+45*x^2+20*x^3+(5-28*x-5*x^4+26*x^2-44*x^3)*f(x)+(-275*x^2-11+110*x+11*x^4)*f(x)^2 ogf
A106804 7.66739 -(-11+108*x-265*x^2-8*x^3+27*x^4+8*x^5)/(4*x^2+9*x-2)/(x^2+5*x-1)/(x^2-5*x+1) lgdogf

one is the factor of the other, and with a score of 15.2226 which is pretty high.

  Best Regards,
  Simon Plouffe





Le 13/12/2011 23:32, Harvey P. Dale a écrit :
> 	There seem to be several problems with the above sequence:
>
> 1.  The definition does not generate the terms of the sequence, but a
> different generating function does.  The g.f. that works is:
>
>                    (-2 x + 9 x^2 + 4 x^3)/(-1 + 10 x - 25 x^2 + x^4)
>
> 2.  The Mma program that is given does not generate the terms of the
> sequence.
>
> 3.  There is a fairly simple linear recurrence that does generate the
> terms of the sequence:
>
>                 a(0)=0, a(1)=2, a(2)=11, a(3)=56,
> a(n)=10*a(n-1)-25*a(n-2)+0*a(n-3)+a(n-4)
>
> 4.  The Extension field says that the sequence was "Edited by the
> Associate Editors of the OEIS, Apr 09 2009" which puzzles me given the
> above problems.
>
> 	I am not sure of how best to proceed.
>
> 	Best,
>
> 	Harvey
>
>
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>
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>



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