Zero is the additive identity of the natural numbers. The concept dates back to 1770 BC. The background celebrates the work of Atiyah and Singer.

One is the multiplicative identity of the natural numbers. It is the additive generator of the natural numbers. The background celebrates the work of Serre.

Two is the smallest prime number. It additive generates the even numbers. The background celebrates the work of Adams.

Three is the smallest odd prime number. The background celebrates the work of Chenciner and Montgomery.