{{{1}}}{{{2}}}
An alias for {{su}}: {{sup sub|X|Y}} → {{su|p=X|b=Y}}.
{{sup sub | superscript | subscript}} produces:
{{sup sub | superscript | subscript}}
To get: ∑n−1k−1(2g)
You would use: {{larger|∑}}{{sup sub|''n''−1|''k''−1}}{{larger|(}}{{sup sub|2|''g''}}{{larger|)}}