Fibonacci's sequence enters European mathematics

1221

Scholars across Italy began studying the rabbit-breeding problem from Leonardo of Pisa's Liber Abaci, in which each generation's count followed a pattern of additive growth. Merchants adopted his Hindu-Arabic numerals for their ledgers. The sequence itself would surface in the spirals of pinecones, sunflower heads, and Renaissance architecture long before anyone understood why nature so persistently favored it.