The Ishango bone is a tally stick, made of bone, which contains sequences of prime numbers, and some series of multiples. It has three rows of notches, with one of the columns having 11, 13, 17, and 19 notches. Originally from Africa, this artifact now resides at the Musee d'Histoire Naturelle , Brussels, Belgium. The bone is dated from around 20,000 BC.

References

• Mathematicians of the African Diaspora
• ISGEm Newsletter