Issue 3292: Fixup to the Sequence docs.

Doc/library/stdtypes.rst

@@ -846,7 +846,7 @@ operations have the same priorities as the comparison operations.  The ``+`` and
 
 This table lists the sequence operations sorted in ascending priority
 (operations in the same box have the same priority).  In the table, *s* and *t*
-are sequences of the same type; *n*, *i* and *j* are integers:
+are sequences of the same type; *n*, *i*, *j* and *k* are integers.
 
 +------------------+--------------------------------+----------+
 | Operation        | Result                         | Notes    |