Hi,
It looks like you are treating TiddlyWiki and widgets like a programming language, trying to do iteration in each loop. That doesn't work.
Take a look at the "counter" attribute in list widget. That is a relatively new feature to help handle what you are doing.
To get the desired output:
<$list filter="[tag[TableOfContents]]" counter="a">
<$text text={{{ [<a>multiply[2]]}}}/> <<currentTiddler>> <br/>
</$list>