Addition chain data

[Hugo Pfoertner]

David Wilson wrote:
> 
> I have compiled a text database of shortest addition chains for all 1 <= n <=
> 1024.
> 
> The uncompressed size of the database is about 64 Mb.  I have .tgz and .zip
> versions of
> the database, each about 5.5 Mb.
> 
> If I can figure out a way to send the files, I will be willing to send a copy to
> anyone who
> asks, especially if someone wishes to make the data available on the net in some
> form.
> 
> --------------------------------
> - David Wilson

David, many thanks for making this table avialable.

For the next few days the table can be downloaded (5.39 MB) from
http://www.enginemonitoring.net/math/ac.zip

It would be nice if someone with enough webspace could add some
navigation and make the content permanently available. Currently there
seems to be no place on the web from where shortest addition chains for
a given n can be downloaded. My
http://www.randomwalk.de/sequences/addchains.txt
which is an extension of
http://www.research.att.com/~njas/sequences/a003313.txt
has only one example of a shortest addition chain for each n up to 2048.

David's tables contains up to 33076 different chains for a single n,
that occur for n=758. It confirms the terms up to n=1000 of

"record values in
http://www.research.att.com/~njas/sequences/A079300" that were sent to
me by Neill Clift some time ago: (NMC=number of minimal addition chains)
>
> NMC(1)=1
> NMC(5)=2
> NMC(7)=5
> NMC(11)=15
> NMC(19)=33
> NMC(22)=40
> NMC(29)=132
> NMC(47)=220
> NMC(58)=352
> NMC(71)=1258
> NMC(127)=2661
> NMC(142)=3903
> NMC(191)=9787
> NMC(446)=12989
> NMC(508)=17961
> NMC(607)=31373
> NMC(758)=33076
> NMC(1087)=55262
> NMC(1214)=110624
>

Hugo Pfoertner