update the power of two formulas to match the RFC text

specification.markdown

@@ -355,20 +355,20 @@ Table: Examples of determining the end of an Unknown-Sized Element
 For Element Data Sizes encoded at octet lengths from one to eight,
 [@tableVintRangePerLength] depicts the range of possible values 
 that can be encoded as an Element Data Size. An Element Data Size with an
-octet length of 8 is able to express a size of 2^56^-2 or
+octet length of 8 is able to express a size of 2^(56)^-2 or
 72,057,594,037,927,934 octets (or about 72 petabytes). The maximum possible
 value that can be stored as Element Data Size is referred to as VINTMAX.
 
 Octet Length | Possible Value Range
 -------------|---------------------
-1            | 0 to  2^7^ - 2
-2            | 0 to 2^14^ - 2
-3            | 0 to 2^21^ - 2
-4            | 0 to 2^28^ - 2
-5            | 0 to 2^35^ - 2
-6            | 0 to 2^42^ - 2
-7            | 0 to 2^49^ - 2
-8            | 0 to 2^56^ - 2
+1            | 0 to  2^(7)^ - 2
+2            | 0 to 2^(14)^ - 2
+3            | 0 to 2^(21)^ - 2
+4            | 0 to 2^(28)^ - 2
+5            | 0 to 2^(35)^ - 2
+6            | 0 to 2^(42)^ - 2
+7            | 0 to 2^(49)^ - 2
+8            | 0 to 2^(56)^ - 2
 Table: Possible range of values that
 can be stored in VINTs, by octet length{#tableVintRangePerLength}