rev correction

content/ctf-writeups/bcactf_5.0/rev.md

@@ -91,19 +91,14 @@ $$
 $$
 sum(comb(\{a_1, a_2, a_3\})) = \frac{(a_1 + a_2 + a_3)^2 - (a_1 + a_2 + a_3)}{2}  
 $$
-
-
-
-
 In general:
-
-$$
-sum(comb(\{a_1, a_2, a_3, ...a_n\})) = \frac{\sum{a_i}* (\sum{a_i}-1)}{2}    
 $$
+sum(comb(\{a_1, a_2, a_3, ...a_n\})) = \frac{\sum{a_i}* (\sum{a_i}-1)}{2} 
+$$   
 
-or,
+or, 
 
-$$ 
+$$
 sum(comb(comb(\{a_1, a_2, a_3, ...a_n\}))) = \frac{\sum{a_i} * (\sum{a_i}-1) * (\sum{a_i}-2) * (\sum{a_i}+1)}{8}
 $$