sed -n means surpress printout unless specifically commanded. Thus, without a "p", you'll get nothing.
The "d" command deletes the entire line
which contains the match--and it goes after
the pattern to be matched.
To delete an instance of "^ + any number", I think it would look something like this:
cat <filename>|sed 's/\^[0-9]//' > <newfilename>
Here's a good tutorial on sed: http://www.grymoire.com/Unix/Sed.html#uh-8