When clicking on the "internal" format link, spaces are collapsed, which is particularly ugly esp. in the EXAMPLE section where he often have "monospace" formatted tables and other "ASCII art".
Consider e.g. https://oeis.org/A257770/internal vs https://oeis.org/A257770

The "internal format" display should somewhat ressemble to what's in the text area when we click "edit internal format", cf. https://oeis.org/edit?seq=A257770&internal=1

I believe this could be fixed by adding CSS style "white-space: pre" for the <tt> tags.

However, when I looked at the source of the ".../internal" page (Ctrl-U in Chrome), I saw something horrible:
The main content (i.e., the OEIS record in internal format as it appears also in the "internal editing" textarea)
is in one <div>, and each line is of the form

<p style="text-indent: -2em; margin-left: 2em; margin-top: 0; margin-bottom: 0;"><tt>%I ... </tt></p>

I strongly suggest to remove all this repeated "inline" style which uselessly fills up more than half of the page, and put just one single line

<style> div p tt {text-indent: -2em; margin: 0 0 0 2em;} </style>

somewhere earlier in the page.

(I checked that there is no other occurrence of the <tt> tag on that page, but of course nothing forbids (and best practice would rather suggest) to add an id or a class attribute to that <div> that holds the main content, and add this specification (#data or .data) to the <style> selector.)

That said, the simplest solution might be to replace that entire <div> with a <pre> tag instead, getting rid of all the <p> and <tt> tags.