kill(all)$

 van=facebook.com/LearningCalculus$

 'sum(2*p-1+2*p, p, s, e);

 for s:1 thru 49 do
     for e: s thru 50 do
         (
             Sum: sum(2*p-1+2*p, p, s, e),
             if Sum = 525 then
                 print("Answer ", Sum, s, e)
         )$

       The first page was torn out so the answer is 3,
       the sum of the numbers on page 1 which were 1 and 2.
       There are three solutions,
       but only one of them has a single page torn out.