Update docs for namedtuple's renaming change.
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 50817b0..2e6a537 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -625,7 +625,7 @@
If *rename* is true, invalid fieldnames are automatically replaced
with positional names. For example, ``['abc', 'def', 'ghi', 'abc']`` is
- converted to ``['abc', '_2', 'ghi', '_4']``, eliminating the keyword
+ converted to ``['abc', '_1', 'ghi', '_3']``, eliminating the keyword
``def`` and the duplicate fieldname ``abc``.
If *verbose* is true, the class definition is printed just before being built.