Esprit Scholengroep English and Dutch. The Cartesius Lyceum is named after French philosopher René Descartes and uses his famous quote "Cogito ergo sum" in their logo. In 1954, the Spinoza Lyceum (also part of the Esprit scholengroep) had a lack of space. They added two classrooms in the Western part of Amsterdam. These became the "Cartesius Lyceum" in 1956. A larger school building was opened by former Queen Juliana in 1962. After merging with another school in 1988, the number of students decreased. In 1999 the Cartesius Lyceum moved close to Jordaan where no secondary schools were yet situated. The European School
Descartes number only one currently known. If is an odd almost perfect number, that is, and is taken as a 'spoof' prime, then is a Descartes number, since . If were prime, would be an odd perfect number. Descartes number In number theory, a Descartes number is an odd number which would have been an odd perfect number, if one of its composite factors were prime. They are named after René Descartes who observed that the number would be an odd perfect number if only were a prime number, since the sum-of-divisors function for would satisfy, if 22021 were prime, where we