Heh, okay, yeah, lemme try and rephrase it...
When you're looking up a move in the 'dex, if there are lots of Pokemon that learn it (I think it's like 50+ or something) then it'll give you a link which'll send you to a list of Pokemon, 50 to each page. The first page works fine, but if there are more than 50 Pokemon in the list, when you click onto page two it'll just revert into a list of all Pokemon in the National Dex.
So basically, it's impossible to tell what Pokemon beyond number 50 can learn that move by tutoring.
Seismic Toss:
http://veekun.com/dex/moves/seismic%20toss
By tutor:
Too many to list!
Crystal: 0
Emerald: 127
FireRed/LeafGreen: 127
Diamond/Pearl: 0
So we click for FR/LG, which is what I'm interested in, and get this:
http://veekun.com/dex/pokemon/search?move=Seismic+Toss&move_method=tutor&move_version=frlg
No problems yet. 127 Pokémon found. I wanna know what other Pokemon can learn this beyond Jigglypuff, though, so I click on page 2:
http://veekun.com/dex/pokemon/search?move=Seismic%252BToss;move_version=frlg;skip=50;move_method=tutor
Here's where our problem appears - 493 Pokémon found.

"I know a lot of kids in my street who, when we wirelessly battle, always have a loppuny. When I ask em why, they always say they think she's hot and some say their dad agrees with them."