[seqfan] Re: shortest addition-subtraction-multiplication chain

[Heinz, Alois]

And:
https://oeis.org/A217032
Minimum number of steps to reach n! starting from 1 and using
the operations of multiplication, addition, or subtraction.

Am 20.01.2013 21:01, schrieb Rob Pratt:
> http://oeis.org/A173419
>
> On Jan 20, 2013, at 2:54 PM, "Max Alekseyev" <maxale at gmail.com<mailto:maxale at gmail.com>> wrote:
>
> SeqFans,
> Recent Al Zimmermann's programming contest basically asks for
> computing a shortest addition-subtraction-multiplication chain for n!:
> http://www.azspcs.net/Contest/Factorials
> Is there a sequence in the OEIS that gives the length of such chain
> for n (not factorial)? It should be hard to compute it for small n.
> Regards,
> Max