Fix link formatting in Beal.ipynb

ipynb/Beal.ipynb

@@ -29,7 +29,7 @@
     "> <br>and $x, y, z$ are all greater than $2$, \n",
     "> <br>then $A, B$ and $C$ must have a common prime factor.\n",
     "\n",
-    "[Andrew Wiles](https://en.wikipedia.org/wiki/Andrew_Wiles) proved Fermat's theorem in 1995, but Beal's conjecture remains unproved, and Beal has offered [one million dollars](http://www.ams.org/profession/prizes-awards/ams-supported/beal-prize) for a proof or disproof. I don't have the mathematical skills of Wiles, so I could never find a proof, but I can write a program to search for  counterexamples. I first wrote [that program in 2000](http://norvig.com/beal2000.html), and [my name got associated](https://www.google.com/webhp?#q=beal conjecture) with Beal's Conjecture, which means I get a lot of emails with purported proofs or counterexamples (many asking how they can collect their prize money). So far, all the emails have been wrong. This notebook catalogs some of the more common errors, updates my 2000 program, and introduces this tool for verifying counterexamples:\n",
+    "[Andrew Wiles](https://en.wikipedia.org/wiki/Andrew_Wiles) proved Fermat's theorem in 1995, but Beal's conjecture remains unproved, and Beal has offered [one million dollars](http://www.ams.org/profession/prizes-awards/ams-supported/beal-prize) for a proof or disproof. I don't have the mathematical skills of Wiles, so I could never find a proof, but I can write a program to search for  counterexamples. I first wrote [that program in 2000](http://norvig.com/beal2000.html), and [my name got associated](https://www.google.com/webhp?#q=beal-conjecture) with Beal's Conjecture, which means I get a lot of emails with purported proofs or counterexamples (many asking how they can collect their prize money). So far, all the emails have been wrong. This notebook catalogs some of the more common errors, updates my 2000 program, and introduces this tool for verifying counterexamples:\n",
     " \n",
     "\n",
     "| [**Online Beal Counterexample Checker**](http://norvig.com/bealcheck.html)  |\n",