[seqfan] Re: exp(sin(x))

[Charles Greathouse]

I think you should submit a comment to the sequence to this effect.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Thu, Apr 29, 2010 at 3:16 PM,  <franktaw at netscape.net> wrote:
> Never mind. I had no sooner walked away from the computer than I
> realized that this is completely straightforward.
>
> Franklin T. Adams-Watters
>
> -----Original Message-----
> From: franktaw at netscape.net
>
> A003724, the number of set partitions of n objects into odd blocks, is
> the exponential expansion of exp(sinh(x)).
>
> It appears that A002017, the expansion of exp(sin(x)), is the number of
> set partitions of n objects with an even number of parts of size == 3
> (mod 4), minus the number of such partitions with an odd number of
> parts of size == 3 (mod 4). I have manually verified this through n =
> 8. Can someone confirm (i.e., prove) it?
>
> Franklin T. Adams-Watters
>
>
>
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