- Paulo Coelho (Wikipedia)
Paulo Coelho de Souza (/ˈkwɛl.juː, kuˈɛl.juː, -joʊ/ KWEL-yoo, koo-EL-yoo, -yoh, Portuguese: [ˈpawlu kuˈeʎu]; born 24 August 1947) is a Brazilian lyricist and novelist and a member of the Brazilian Academy of Letters since 2002. His novel The Alchemist became an international best-seller and he has published 30 more books since then.
- Catalan number (Wikipedia)
In combinatorial mathematics, the Catalan numbers are a sequence of natural numbers that occur in various counting problems, often involving recursively defined objects. They are named after the French-Belgian mathematician Eugène Charles Catalan.