Not every time is the music that the Perl Weekly Challenge inspires going to be a Broadway show tune, a banger from classic rock, or even a baroque fugue. Sometimes, it’s going to be a marketing jingle: 🎶 Double your pleasure, double your fun, with double good, double good, Doublemint Gum! 🎶

See, it’s because “Luhn” rhymes with fun. No? Fine, let’s chew on Perl Weekly Challenge 290 for a little bit.