[seqfan] Internal format examples page needs updating

[jnthn stdhr]

If one edits a page using the "edit internal format" link and  follows the
instructions in https://oeis.org/eishelp1.html, saving changes chokes on
most lines that begin with "%x Axxxxxx", per the instructions and examples.

Also, why doesn't the %S line get automatically shortened when entries are
longer than 260 characters? It would save time for both submitters and
editors.  If a sequence must use more characters, a special symbol could be
used to override the limit when parsed.

-Jonathan