Not “page 42 and the following”. The adjective following calls for a noun. It looks like you're using “the following” to mean “what follows the current point in the text” or “something that follows” or “the next few lines”.
“Page 42 and the following pages” sounds correct. This could be shortened to “page 42 and following pages” (since you aren't specifying the exact number of following pages, it's some following pages, so the null article works), or perhaps even to “page 42 and following” (without the, it doesn't look like a noun is missing any more).
In practice, you would normally not spell this out, but use the abbreviation ff. The word page becomes plural since it now designates not just to the first page but to the whole sequence.
(…) can be found on pages 42ff."