Catalan-like array with digits
Marc LeBrun
mlb at well.com
Mon Aug 20 23:38:01 CEST 2007
Gottfried,
I have not got your question.
Do you ask help in identifying your sequences? If so, did you try to
feed them to Superseeker?
In general, it is hard to guess the nature of a new sequence just from
numerical values. It would make much sense if you provided detailed
description of how to compute the numerical values of your sequence.
The current description ("context") is rather obscure.
Regards,
Max
On 8/20/07, Gottfried Helms <Annette.Warlich at t-online.de> wrote:
> Dear seqfans -
>
> I have a difficult sequence, not in OEIS:
>
> let n begin at 1, then I have the sequence:
>
> a(n)= 1/2 -1/12 1/48 -1/180 11/8640 -1/6720 -11/241920 29/1451520
> 493/43545600 -2711/239500800 -6203/3592512000 2636317/373621248000
> -10597579/10461394944000 -439018457/78460462080000 ...
>
> if I rescale
>
> b(n) = a(n)*n*n! *(n+1)!
>
> I seem to get integers:
>
> b(n)= 1 -1 3 -16 110 -540 -9240 292320
> 14908320 -1639612800 -33013854720 21046667685120
> -549927873855360 -637881314775344640
>
> another rescaling, perhaps a bit more smooth, is
>
> c(n) = a(n)*((n+1)!)^2
>
> c(n)= 2 -3 12 -80 660 -3780 -73920 2630880
> 149083200 -18035740800 -396166256640 273606679906560
> -7698990233975040 -9568219721630169600 ...
>
> I can create this series by matrix-logarithm and exponentiation
> to some finite extent, but to discuss things analytically it would
> be good to have a more direct description.
>
> Someone an idea?
>
>
> Context:
> It occurs in the core of a tetration-formula, where
>
> f_s: x:= s^x - 1
>
> and f_s is iterated. The special interest of these coefficients is,
> that they allow to define a powerseries in y,x,log(s) for fractional
> iterates of f_s, where y denotes the fractional value for the iteration.
>
>
> Gottfried
>
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