Redirect url with parameters to readable url

Question

I've recently changed my urls with parameters to more readable urls with the following htaccess:

RewriteRule ^page/([A-Za-z0-9-+_\s]+)$ /index.php?n=$1 [L]
RewriteRule ^category/([A-Za-z0-9-+_\s]+)/([0-9]+)$ /index.php?p=$1&b=$2 [L]

I believe this poses problems now with duplicate content on the search engines, as index.php urls and domain.com/page/ urls will both be indexed.

If calls made to domain.com/page/1 get redirected to index.php?n=1 how can I redirect requests made to index.php to domain.com/page/ ??

My attempt to do so is giving me a 404 code sending me to domain2.

#RewriteCond %{QUERY_STRING} ^n=([A-Za-z0-9]+)$ [NC]
#RewriteRule ^index\.php$ http://domain.com/page/? [R=301,L]

htaccess

IndexIgnore *
ErrorDocument 404 http://domain2.com


#REDIRECTS
Redirect 301 /keyword.php http://domain.com
Redirect 301 /inc/keyword.php http://domain.com




Options +FollowSymlinks
RewriteEngine on

#Redirect all pages in a folder to a single URL
RewriteRule ^test/(.*)$ http://domain.com [L,R=301]

# HTTP HOST, escape . and start string with ^
RewriteCond %{HTTP_HOST} ^www\.domain\.com [NC]
RewriteRule ^(.*)$ http://domain.com/$1 [R=301,NC] 


RewriteCond %{QUERY_STRING} ^p=h&m=([A-Za-z]+)&y=([0-9]+)$ [NC]
RewriteRule ^index\.php$ http://domain.com? [R=301,L]


#RewriteCond %{QUERY_STRING} ^n=([A-Za-z0-9]+)$ [NC]
#RewriteRule ^index\.php$ http://domain.com/page/? [R=301,L]


RewriteRule ^page/([A-Za-z0-9-+_\s]+)$ /index.php?n=$1 [L]

RewriteRule ^category/([A-Za-z0-9-+_\s]+)/([0-9]+)$ /index.php?p=$1&b=$2 [L]

Answer 1

Instead of your commented 301 rule try this one:

RewriteCond %{THE_REQUEST} /index\.php\?n=([^\s&]+)&y=([^\s&]+) [NC]
RewriteRule ^ /page/%1/%2? [R=301,L]

RewriteCond %{THE_REQUEST} /index\.php\?n=([^\s&]+) [NC]
RewriteRule ^ /page/%1? [R=301,L]