Welcome to the 241st Carnival of Mathematics, hosted here at the home of the Carnival, The Aperiodical. The Aperiodical is a shared blog written and curated by Katie Steckles (me), Christian Lawson-Perfect and Peter Rowlett, where we share interesting maths news and content, aimed at people who already know they like maths and would like to know more. The Carnival of Maths is administered by the Aperiodical, and if you’d like to host one on your own blog or see previous editions, you can visit the Carnival of Maths page.